U.S.S. TINOSA (SS-283) — war patrol report SS-283_TINOSA_Part2.pdf

— page 7 —
The provided image is a page from a WWII submarine patrol report. I will transcribe the text exactly as it appears, preserving line breaks and capitalization. There are no handwritten annotations or stamps on this particular page.

Subject: U.S.S. TINOSA (SS283) - Report of Seventh War Patrol.

— page 9 —
CONFIDENTIAL
Subject: U.S.S. TILOSA (SS263) - Report of Seventh War Patrol.
(C) WEATHER:

Majuro to Bonins: Very calm seas with light winds from
Southeast.
North of Bonins: Encountered one day of mountainous seas
and typhoon winds (45 to 50 knots from Northeast).
Bonins to area: Moderate seas and winds with skies overcast.
In area: Moderate seas and winds with about 30% of the days
completely overcast.
Area to Midway: Moderate seas, moderate winds (up to 15
knots) from Southeast and East. Visibility generally good.

(D) TIDAL INFORMATION:
No unusual tides or currents were encountered.

(E) NAVIGATIONAL AIDS:
Since it was overcast approximately 30% of the time in the
area it was often necessary to obtain positions with radar ranges
and bearings. The numerous high peaks in the area made possible
good position cuts by this means.
On days when the sky was clear high peaks were visible at
a range as high as 85 miles. On clear starlight nights, with
or without moonlight, these peaks were visible as far as 45 miles.
Navigational lights were observed as follows:

| NAME | CHARACTERISTICS | REMARKS |
|---|---|---|
| Caja Shima | : Fl. period 14 sec. | : Yes - normal intensity |
| | | : observed at 2 miles. |
| | | : |
| | | : |
| Ie Shima | : Gr. Fl. period 49 sec. | : Yes - normal intensity, |
| (Banjo Gunto) | : 2 Fl in 20 sec, 29 sec ecl | : observed at 27 miles |
| | : G. Fl. per 37 sec. | : |
| | : 3 Fl in 14 sec. 23 sec ecl: as observed later. |
| | | : |
| | | : |
| Gyu To. | : Gr. Fl. period 6 sec. | : Yes - normal intensity |
| | : 2 Fl in 1½ Sec. 4½ Sec. ecl | : observed at 14 miles |

ENCLOSURE (A)
[HANDWRITTEN: -26-]

— page 10 —
CONFIDENTIAL
Subject: U.S.S. THRESHER (SS203) - Report of Seventh War Patrol.
(L) Continued

NAME                 CHARACTERISTICS                     REMARKS

— page 13 —
CONFIDENTIAL
G)
U.S.S. TINOSA (SS283)
AIRCRAFT CONTACTS (REVISED)

| | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| CONTACT NUMBER | | | | | | | |
| Date | :6/13: | :6/13: | :6/16: | :6/16: | :6/16: | :6/16: | :6/16: |
| | : 1944 : | : 1944 : | : 1944 : | : 1944 : | : 1944 : | : 1944 : | : 1944 : |
| Time (Zone) | : 0942 : | : 1122 : | : 0733 : | : 0955 : | : 1310 : | : 1426 : | : 1325: |
| | : (K) : | : (K) : | : (I) : | : (I) : | : (I) : | : (I) : | : (I) : |
| Position: Lat. | : 29°- 36.0N : | : 29°- 34.0 N : | : 29°- 38.0 N : | : 29°- 01.0 N : | : 29°- 14.0 N : | : 29°- 36.0 N : | : 33°- 17.0 N : |
| Long. | : 151°- 26.0 : | : 150°- 57.0 : | : 136°- 23.0 : | : 136°- 01.0 : | : 135°- 24.0 : | : 135°- 14.0 : | : 127°- 17.0 : |
| Speed | : 15 Knots : | : 15 Knots : | : 15 Knots : | : 15 Knots : | : 15 Knots : | : 15 Knots : | : 15 Knots : |
| Course | : 270°T : | : 270°T : | : 267°T : | : 267°T : | : 267°T : | : 350°T : | : |
| Trim | : Surf. : | : Surf. : | : Surf. : | : Surf. : | : Surf. : | : Surf. : | : |
| Minutes Since Last | | | | | | | |
| SD Radar Search | : | : | : 0 : | : 0 : | : | : | : | Number | : 1 : | : 1 : | : 1 : | : 1 : | : 1 : | : 1 : | : |
| Type | : Emily : | : Betty : | : Un : | : Un : | : Un : | : Un : | : |
| Probable Mission | : Pat. : | : Pat. : | : Pat. : | : Pat. : | : Trans. : | : Pat. : | : |
| How contacted | : out : | : OOD : | : Radar : | : Radar : | : out : | : Radar : | : |
| Initial Range | : 10 miles : | : 7 miles : | : 4 miles : | : 6 miles : | : 7 miles : | : 14 miles : | : |
| Elevation Angle | : 4° : | : 4° : | : Unk : | : Unk : | : 3° : | : Unk : | : |
| Range & Relative | | | | | | | |
| Bearing of Plane | | | | | | | |
| When It Detected | | | | | | | |
| S/L. | : ND : | : ND : | : Unk : | : Unk : | : ND : | : Unk : | : |
| Sea: (State (Beau- | : 1 : | : 1 : | : 3 : | : 3 : | : 2 : | : 2 : | : 2 : |
| fort) | | | | | | | |
| (Direction (Rel) | : | : | : | : | : | : | : |
| Visibility (Miles) | : 15 mi. : | : 15 mi. : | : 5 mi. : | : 5 mi. : | : 15 mi. : | : 15 mi. : | : 15 mi. : |
| Clouds: (Height in | : 10,000 : | : 10,000 : | : 4,000 : | : 4,000 : | : 6,000 : | : 4,000 : | : 4,000 : |
| Ft. | | | | | | | |
| (Percent | : 20% : | : 40% : | : 70% : | : 70% : | : 60% : | : 70% : | : 70% : |
| Overcast | | | | | | | |
| (Bearing (Rel) | : | : | : | : | : | : | : |
| Moon: (Angle | : - : | : - : | : - : | : - : | : - : | : - : | : - : |
| (Percent | | | | | | | |
| Illum. | : - : | : - : | : - : | : - : | : - : | : - : | : - : |

Type of S/L. Camouflage on this patrol 342/35-B
ENCLOSURE (A)

-30-

— page 14 —
[CROSSED OUT: CONFIDENTIAL]
(G) CONTINUED
CONTACT NUMBER

U.S.S. TINOSA (SS283)
AIRCRAFT CONTACTS (REVTS.)

| | 8 | 9 | 10 | 11 | 11 | 11 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|
| Date | 6/19/ | 6/19 | 6/20/ | 6/21/ | 6/21/ | 6/21/ | 6/21/ | 6/21/ |
| | : 44 | : 44 | : 44 | : 44 | : /44 | : 44 | : 44 | : 44 |
| Time (Zone) | 0840 | 1055 | 1900 | 0820 | 0845 | 0940 | 1042 | 1610 |
| | (I) | (I) | (I) | (I) | (I) | (I) | (I) | (I) |
| Position: Lat. | 33 | 33 | 33 | 32 | 32 | 32 | 32 | 32 |
| | 37 N | 43 N | 18 N | 11 N | 09 N | 10 N | 12 N | 35 N |
| Long. | 128 | 128 | 127 | 127 | 127 | 127 | 127 | 127 |
| | 27 E | 57 E | 09 E | 17 E | 18 E | 22 E | 27 E | 38 E |
| Speed | 12 Kts | 12Kts | 12Kts | 12Kts | 2 Kts | 2 Kts | 2 Kts | 12 Kts |
| Course | 080 | 080 | 235 | 070 | 070 | 070 | 070 | 340 |
| Trim | Surf. | Surf. | Surf. | Surf. | Per. | Per. | Per. | Surf. |
| Minutes Since Last SD Radar Search | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Number | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Type | Un | Un | Un | Un | Betty | Betty | Betty | Un |
| Probable Mission | Pat | H | H | H | H | H | H | H |
| How Contacted | SD Radar | SD Radar | COD | SD Radar | Per | Per | Per | SD Radar |
| Initial Range | 14 Mi. | 16 Mi. | 12 Mi. | 3 Mi. | 1 Mi. | 4 Mi. | 4 Mi. | 9 Mi. |
| Elevation Angle | Unk | Unk | 6° | Unk | 3° | 8° | 2° | Unk |
| Range & Relative Bearing of Plane When It Detected S/M | Unk | ND | ND | ND | 090° | 107° | 180° | ND |
| | | | | | 1 Mi | 4 Mi | 4 Mi | |
| Sea: (State (Beaufort | 3 | 3 | 3 | 1 | 1 | 2 | 2 | 2 |
| Direction (Rel) | 000 | 000 | 200 | 005 | 005 | 005 | 005 | 090 |
| Visibility (Miles) | 15 | 15 | 15 | 7 | 7 | 7 | 7 | 12 |
| Clouds: (Ht in Ft. | 4,000 | 5,000 | 5,000 | 4,000 | 4,000 | 4,000 | 4,000 | 15,000 |
| (Percent Overcast | 80% | 70% | 40% | 100% | 100% | 100% | 100% | 50% |
| Moon: (Bearing (Rel) | - | - | - |

— page 15 —
CONFIDENTIAL
(G) (Con't)
CONTACT U.S.B.R
U.S.S. TINOSA (SS283)
AIRCRAFT CONTACT (REVISED)

| | : 13 | : 14 | : 15 | : 16 | : 17 | : 18 | : 19 |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| Date | : 6/27/ | : 6/28/ | : 6/28/ | : 7/2/ | : 7/5/ | : 7/9/ | : 7/10/ |
| | : 1944 | : 1944 | : 1944 | : 1944 | : 1944 | : 1944 | : 1944 |
| Time (Zone) | : 1000 | : 1017 | : 1343 | : 0520 | : 1245 | : 1600 | : 1245 |
| | : (I) | : (I) | : (I) | : (I) | : (I) | : (I) | : (I) |
| Position: Lat. | : 32 | : 32 | : 32 | : 33 | : 30 | : 32 | : 32 |
| | : 04 N | : 41 N | : 43 N | : 38 N | : 21 N | : 43 N | : 13 N |
| Long. | : 129 | : 126 | : 126 | : 127 | : 125 | : 127 | : 126 |
| | : 20 E | : 19 E | : 14 E | : 38 E | : 21 E | : 43 E | : 43 E |
| Speed | : 2 | : 11 | : 2 | : 17 | : 2 | : 12 | : 6 |
| | : Kts. | : Kts. | : Kts. | : Kts. | : Kts. | : Kts. | : Kts. |
| Course | : 000T | : 302T | : 302T | : 245T | : 090T | : 255T | : 050T |
| Tri | : Rad. | : Surf. | : Peri. | : Surf. | : Peri. | : Surf. | : Surf. |
| Minutes Since Last | : | : | : | : | : | : | : |
| SD Radar Search | : 0 | : 0 | : 0 | : 2 | : 0 | : 2 | : 0 |
| Number | : 1 | : 1 | : 1 | : 2 | : 1 | : 1 | : 1 |
| Type | : Pete | : Unk | : Unk | : Betty | : Betty | : Jake | : Unk |
| Probable Mission | : Pat | : Unk | : Unk | : H | : Pat | : Pat | : Pat |
| How Contacted | : Peri-SD | : Peri-SD | : Peri-Loo- | : Peri-Loo- | : Peri-Look- | : SD | : SD |
| | : scope, radar | : scope, radar | : scope, outs | : scope, outs | : scope, outs | : radar | : radar |
| Initial Range | : 4 | : 8 | : 8 | : 10-03 | : 8 | : 8 | : 6 |
| | : miles | : miles | : miles | : miles | : miles | : miles | : miles |
| Elevation Angle | : 80 | : Unk | : 10 | : 50 | : 200 | : 10 | : Unk |
| Range & Relative | : | : | : | : 3 | : | : | : |
| Bearing of Plane | : | : | : | : miles | : | : | : |
| When it Detected S/M | : ND | : Unk | : ND | : 180 | : ND | : ND | : Unk |
| (State (Beaufort) | : 2 | : 2 | : 2 | : 1 | : 2 | : 1 | : 1 |
| (Direction (Rel) | : 270 | : 340 | : 040 | : 045 | : 160 | : 120 | : 190 |
| Visibility (Miles) | : 4 | : 15 | : 20 | : 20 | : 25 | : 40 | : 50 |
| | : miles | : miles | : miles | : miles | : miles | : miles | : miles |
| Clouds: (Height in ft. | : 18, | : 5, | : 5, | : 5, | : 4, | : 7, | : 10, |
| | : 000 | : 000 | : 000 | : 000 | : 000 | : 000 | : 000 |
| (Percent Overcast | : 50% | : 90% | : 95% | : 30% | : 50% | : 80% | : 0% |
| (Bearing (Rel) | : - | : - | : - | : - | : - | : - | : - |
| Moon: (Angle | : - | : - | : - | : - | : - | : - | : - |
| (Percent Illum. | : - | : - | : - | : - | : - | : - | : - |
Type of S/M Camouflage on this patrol 32/305-5

-32-

— page 16 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)
AIRCRAFT CONTACT (REVISED)

(G) (Con't)
CONTACT NUMBER | : 20 : 21 : 21 : 21 : 22 : 23 : 24
Date | : 7/12 : 7/13 : 7/13 : 7/13 : 7/13 : 7/13 : 7/13
| : '44 : '44 : '44 : '44 : '44 : '44 : '44
Time (Zone) | : 0745 : 0834 : 0903 : 0948 : 1033 : 1055 : 1139
| : (I) : (I) : (I) : (I) : (I) : (I) : (I)
Position Lat. | : 32 56 : 30 45 : 30 47 : 30 48 : 30 50 : 30 51 : 30 59
| : N : N : N : N : N : N : N
Long. | : 129 : 129 : 129 : 129 : 129 : 129 : 129
| : 07 : 42 : 41 : 40 : 41 : 41 : 39
Speed | : 2Kts : 2Kts : 2Kts : 2Kts : 2Kts : 2Kts : 2Kts
Course | : 000 : 350 : 350 : 350 : 350 : 350 : 270
Trim | : Per : Per : Per : Per : Per : Per : Per
Minutes Since Last | :
SD Radar Search | : 0 : 0 : 0 : 0 : 0 : 0 : 0
Number | : 4 : 3 : 1 : 2 : 1 : 1 : 1
Type | : 2 Eng :
| : Bomber : Pete : Pete : Pete : Jake : Betty : Tess
Probable Mission | : Trans E : E : E : E : E : E : Trans
How Contacted | : Per. : Per. : Per. : Per. : Per. : Per : Per
Initial Range | : 10 : 10 : 5 : 7 : 6 : 2 : 6
| : Miles : Miles : Miles : Miles : Miles : Miles : Miles
Elevation Angle | : 60 : 50 : 150 : 100 : 50 : 20 : 40
Range & Relative Bearing | :
of plane when it detect- | :
ed S/M | : ND : ND : ND : ND : ND : ND : ND
(State (Beaufort) | : 0 : 1 : 1 : 1 : 1 : 1 : 1
Sea: (Direction(Rel) | : - : 235 : 235 : 235 : 235 : 235 : 315
Visibility (Miles) | : 50 : 50 : 50 : 50 : 50 : 50 : 50
Clouds: { Alt in Ft | : 2000 : 5000 : 5000 : 5000 : 5000 : 5000 : 5000
( Percent Overcast | : 20% : 20% : 20% : 20% : 20% : 20% : 30%
Moon { Bearing (Rel) | : - : - : - : - : - : - : -
( Angle | : - : - : - : - : - : - : -
Percent Illum. | : - : - : - : - : - : - : -
Type of S/M Camouflage on this patrol 32/3S-b INCLOSURE (A)
-33-

— page 17 —
CONFIDENTIAL
U.S.S. TINOS (SS210)
AIRCRAFT CONTACTS (REVISED)

(G) (Con't)
| | : 25 | : 26 | : 27 | : 28 | : 29 | : 30 | : 31 |
|---|---|---|---|---|---|---|---|
| CONTACT NUMBER | | | | | | | |
| Date | 7/14 | 7/14 | 7/14 | 7/14 | 7/15 | 7/21 | 7/21 |
| | '44 | '44 | '44 | '44 | '44 | '44 | '44 |
| Time (Zone) | 0634(I) | 1200 | 1457 | 1515 | 1650 | 0827 | 1102 |
| | : (I) | : (I) | : (I) | : (I) | : (I) | : (I) | : (I) |
| Position: Lat. | : 31 | : 31 | : 31 | : 31 | : 30 | : 29 | : 29 |
| | : 46N | : 48N | : 48N | : 49N | : 21N | : 21N | : 25N |
| Long. | : 127 | : 127 | : 127 | : 127 | : 127 | : 144 | : 145 |
| | : 52E | : 49E | : 43E | : 41E | : 15E | : 42E | : 28E |
| Speed | : 9kts | : 2kts | : 12kts | : 2kts | : 12kts | : 17Kts | : 17-ts |
| Course | : 300 | : 300 | : 300 | : 300 | : 000 | : 085 | : 085 |
| Trim | : Surf | : Per | : Surf | : Per | : Surf | : Surf | : Surf |
| Minutes Since Last | | | | | | | |
| SD Radar Search | : 0 | : 0 | : 0 | : 00 | : 0 | : 0 | : 00 |
| Number | : 1 | : 1 | : 2 | : 1 | : 1 | : 1 | : 1 |
| Type | : Unk | : Betty | : Betty | : 2 Eng. | : Unk | : Mavis | : Mavis |
| Probable Mission | : Unk | : Unk | : H | : Sear | : E | : Pat | : Pat | How Contacted | : SD | : peri- | : lock- | : Peri- | : SD | : SD | : look- |
| | : Radar & | : scope | : out | : scope | : Radar | : Radar & | : outs |
| | : look out | | | | | : look out | |
| Initial Range | : 10 | : 5 | : 5&10 | : 1 | : 4 | : 23 | : 8 |
| | : Miles | : Miles | : Miles | : Mile | : Miles | : Miles | : Miles |
| Elevation Angle | : 40 | : 30 | : 3&50 | : 10 | : - | : 50 | : 20 |
| Range & Relative Bear- | | | | | | | |
| ing of plane when | | | | | | | |
| detected S/M | : ND | : ND | : Unk | : Unk | : Unk | : ND | : Unk |
| Sea: (State (beaufort, | : 3 | : 2 | : 2 | : 2 | : 2 | : 2 | : 2 |
| (Direction (Rel) | : 260 | : 270 | : 290 | : 290 | : 160 | : 165 | : 165 |
| Visibility (Miles) | : 50 | : 50 | : 50 | : 50 | : 50 | : 50 | : 50 |
| Clouds: (Ht in Ft. | : 10000 | : 10000 | : 10000 | : 10000 | : 10000 | : 4000 | : 4000 |
| (Percent over- | | | | | | | |
| cast | : 40% | : 50% | : 50% | : 50% | : 40% | : 8% | : 7% |
| Moon: (Bearing (Rel) | : - | : - | : - | : - | : - | : - | : - |
| (Angle | : - | : - | : - | : - | : - | : - | : - |
| Percent Illum. | : - | : - | : - | : - | : - | : - | : - |

Type of S/M Camouflage on this patrol 32/35-b ENCLOSURE (A)

[HANDWRITTEN: -34-]

— page 18 —
CONFIDENTIAL
(H) ATTACK DATA

Torpedo Attack Report
U.S.S. TINOSA Torpedo Attack No. 1 Patrol No. 7
Time - 2112 GCT Date 14 June 1944 Lat. 29°-30' N. Long. 140°-23'E.
Target Data - Damage Inflicted

Description: 2 Small AO (2800 Tons) in convoy with one medium
and a 2DD escort. Initial contact by sight on
surface with 12,000 yards visibility.

Ships sunk: None.
Ship(s) damaged or
Probably Sunk: None.
Target draft: 15' Course: 020° Speed: 6.5 knots Range: 3200 Yards

Own Ship Data
Speed: 3 knots Course: 090° Depth: 63 feet Angle: 10 rise

Fire Control and Torpedo Data
Type attack: Periscope attack. Used TDC solution in conjunction
with periscope observations for solution of target course and
speed. Faulty speed solution caused misses ahead of target.
Possibly detected prior to firing.

|                   | #1      | #2      | #3      | #4      | #5      | #6      |
| :| :------ | :------ | :------ | :------ | :------ | :------ |
| Tubes Fired       | #1      | #2      | #3      | #4      | #5      | #6      |
| Track Angle       | 111F    | 111F    | 111F    | 116F    | 116F    | 116F    |
| Gyro Angle        | 358°    | 358°30' | 358°30' | 358°30' | 358°30' | 358°30' |
| Depth Set         | 10'     | 10'     | 10'     | 10'     | 10'     | 10'     |
| Power             |         |         |         |         |         |         |
| Hit or Miss       | Miss    | Miss    | Miss    | Miss    | Miss    | Miss    |
| Erratic           | No      | No      | No      | No      | No      | No      |
| MK Torpedo        | 23      | 23      | 23      | 23      | 23      | 23      |
| Serial No.        | 52925   | 41184   | 41283   | 41284   | 41061   | 52907   |
| MK Exploder       | 6-4     | 6-4     | 6-4     | 6-4     | 6-4     | 6-4     |
| Serial No.        | 8567    | 12731   | 8556    | 13141   | 8564    | 460     |
| Actuation Set     | Contact | Contact | Contact | Contact | Contact | Contact |
| Actuation actual  | -       | -       | -       | -       | -       | -       |
| MK Warhead        | 16-1    | 16-1    | 16-1    | 16-1    | 16-1    | 16-1    |
| Serial No.        | 12402   | 13282   | 3423    | 11566   | 12403   | 3305    |
| Explosive         | TNT     | TNT     | TNT     | TNT     | TNT     | TNT     |
| Firing Interval   | 8 seconds                                                   |
| Type Spread       | 4° Div.                                                     |
| Sea Conditions    | Heavy swells. Choppy sea.                                   |
| Overhaul Activity | U.S.S. BUSHNELL (AS15)                                      |

ENCLOSURE (A)

-35-

— page 19 —
CONFIDENTIAL
(H) ATTACK DATA

Torpedo Attack Report

U.S.S. TINOSA Torpedo Attack No. 2 Patrol No. 7
Time - 1412 GCT Date 3 July 1944 Lat. 32°0-24.5'N. Long.128°0-46.5'E
Target Data - Damage Inflicted

Description: Suwa Maru (Large AP), Taihoku Maru (Large AK) in
convoy with another large AK 1 AO, 1DD, 1 Tug
and 4 smaller escorts: Contact made by SJ radar
at 18,000 yards. 15,000 yards visibility in
bright moonlight.

Ships sunk: 1 large AP, similar to Suwa Maru, 10,800 tons
(EU by ONI Pub)
1 large AK, similar to Taihoku Maru, 8,252 tons
(EU by ONI Pub)

Ships damaged or
Probably Sunk: None.

Damage determined
by: Saw ships sink.

Target #1 Draft - 29' Course 000°(T) - Speed 8.5 - Range: 530 -
yards.
Target #2 Draft - 29' Course 050°(T) - Speed 8.5 - Range:
1,000 yards.

Own Ship Data

Speed 2.5 - Course 068°(T) - Depth: 60 Ft. - Angle 2° Rise.
Speed 2.5 - Course 070°(T) - Depth: 60 Ft. - Angle 2° Rise.

Fire Control and Torpedo Data

Type Attack: Made attack using periscope bearings and SJ radar
ranges with TDC solution of course and speed. At
radar depth until attack phase, then went to
periscope depth. Large gyro angles used on second
target due to need of firing before being driven
down. Three hits out of four torpedoes fired
with large gyro speaks well for the torpedo per-
formance.

- 36 - ENCLOSURE (A)

— page 20 —
CONFIDENTIAL
(H) ATTACK DATA

Torpedo Attack Report
U.S.S. TINOA (SS283) Torpedo Attack No. 2 (Cont) Patrol No. 7

Tubes Fired             #7      #8      #1      #2      #3      #4
Track Angle             110S    112S    92P     90P     96P     104P
Gyro Angle              203.4   204.5   70L     70S     61S     57S
Depth Set               8 Feet  8 Feet  8 Feet  8 Feet  8 Feet  8 Feet
Power                   MK 23           MK 23
Hit or Miss             Hit     Hit     Miss    Hit     Hit     Hit
Erratic                 No      No      No      No      No      No
Mark Torpedo            23      23      23      23      23      23
Serial No.              41061   41288   52915   52824   52942   52668
Mark Exploder           6-4     6-4     6-4     6-4     6-4     6-4
Serial No.              8566    8613    5503    11630   13291   3533
Actuation Set           Contact Contact Contact Contact Contact Contact
Actuation Actual        Contact Contact Miss    Contact Contact Contact
Mark Warhead            16-1    16-1    16-1    16-1    16-1    16-1
Serial No.              9423    9460    13057   11865   13045   13018
Explosive               TPX     TPX     TPX     TPX     TPX     TPX
Firing Interval         13 Seconds              11 seconds
Type Spread             Fired to hit            4° Divergent
Sea Conditions          Moderate swell
Overhaul Activity USS BUSHNELL

[HANDWRITTEN: -37-]
ENCLOSURE (A)

— page 21 —
CONFIDENTIAL
(E) ATTACK DATA
U.S.S. TIROSA (SS283) GUI ATTACK NO. 1 PATROL NO. 7
Time 2110(I) Date 18 June 1944 Lat. 33°-45'N. Long.128°-03' E.

Target Data - Damage Inflicted

Sunk: One four hundred ton, three-masted sailing vessel.
      Length in feet - 150.

Details of Action

Commenced firing with all guns (one four inch 50 cal. two
20 MM. and two 50 Cal. MG) at an initial range of 750 yards.
High capacity ammunition with fuses set on superquick, as used
in the four inch gun. The first shot was over and the second
was short, ricocheting through the halyards, cutting down the
foremast. At the same time a continuous hail of 20 MM. and 50 Cal.
projectiles was directed at the target, making any enemy action
impossible.

After this first burst of rapid fire, it became apparent
that any further "clean-up" was unnecessary. All rapid fire guns
were ordered to cease firing and an attempt was made to sink the
vessel with 4 inch gunfire. Twenty-two H.C. shells were fired,
only five of which were visible hits, and these did not do the
damage we expected of them. This action took place during a dark
night, and it was difficult for the pointer and trainer to see
the target, even at a range of 500 yards. The range closed from
the opening range of 750 yards to the final range of 100 yards.
At this point the four inch gun was secured and the craft set
afire by going within heaving distance, and throwing oil-soaked
rags, fuel oil, and hand grenades in its superstructure.
When last seen it was low in the water and burning fiercely down
to the water line.

ENCLOSURE (A)
[HANDWRITTEN: -38-]

— page 22 —
CONFIDENTIAL
(H) ATTACK DATA
U.S.S. TINOSA (SS263) GUN ATTACK NO. 2 PATROL NO. 7
Time 1950 (I) Date 22 June 1944 Lat. 33°-43' N. Long.127°-44'E
Target Data - Damage Inflicted

Sunk: One fifty ton diesel powered fishing sampan, 75 feet
in length.

Details of Action
Opened fire with all guns at an initial range of 1,000
yards. High capacity ammunition was used in the four inch gun,
with the fuses set on superquick. The rapid-fire guns had their
usual loadings of one tracer, one incendiary and one common.
The first shot of the four inch was a hit, noticeably lowering
the craft by the stern. After the initial hail of rapid-fire
those guns ceased firing. The second shot from the four inch
hit the cabin, blowing it wide open. The third, last and un-
necessary shot was a hit forward. Although a mass of wreckage,
this vessel was set on fire by heaving oil-soaked rags upon its
topside structure. Upon departure from the locality smoke and
flames literally poured out of the wreckage, making it almost
impossible to see.

ENCLOSURE (A)
[HANDWRITTEN: -39-]

— page 23 —
CONFIDENTIAL
(E) ATTACK DATA
U.S.S. TINOSA. (SS283) GUN ATTACK NO. 3 PATROL NO. 7.
Time 0745(I) Date 10 July 1944 Lat. 32°-12' N Long. 127°-00' E.

Target Data - Damage Inflicted
Sunk: One 90 foot, two masted, ONE hundred ton diesel
powered trawler.

Details of action.
Opened fire with the four inch gun at initial range of 1650
yards. As in the previous actions, the 11 30 -od. 1 nose fuse,
set on superquick, was used on the four inch projectiles. The
first shot was short but ricocheted off the water into the after
part of the vessel, lowering the after mast and blasting the
superstructure. The second shot was also short ricocheting off
the water. The next six shots, fired at a range of one thousand
yards were all misses to the right, due to improperly set de-
flection. The ninth and last shot, fired at a range of five hun-
dred yards was a hit amidships, just above the water line, and in
line with the stack. A beautiful explosion occurred, setting
the vessel fire, and giving her a 30° starboard list. When last
seen the vessel's bow and mast were projecting out of the water,
with a 60° starboard list. No rapid fire guns were used in this
encounter.

ENCLOSURE (A)
[HANDWRITTEN: L-40-]

— page 25 —
CONFIDENTIAL
Subject: U.S.S. ATOSA (S283) - Report of seventh patrol.
(J) ANTI-SUBMARINE TACTICS AND EVASION TACTICS: (Con't)

Evasion tactics were the same as in the first convo attack.

ENGINEERING

1. No. 4 main engine. At 1551 22 June 1944 the overspeed trip
on this engine tripped and caused the engine to stop. On investi-
gation it was found that the overspeed plunger stop and the gover-
nor latch were worn so badly that the engine vibrations would cause
the latch to loose its hold on the stop plunger. Temporary repairs
made by ship's force.

2. No. 2 turbo-blower. At 2006, 17 July 1944 this blower
was put out of commission because when it was operated excessive
noise and vibration occurred. Investigation disclosed that the
labyrinth packing had worn unevenly and that the thrust bearings
appeared to have been pounded out. It is believed that the im-
peller became unbalanced. No repairs made.

3. Condix log. The operation of this log as unreliable
during the patrol; some of the defects found and corrected were:
(a) Leaky bellows unit.
(b) Valves 9 and 10 leaked thus causing unequal pressure
in the bellows unit.
(c) Loose connections on main contactor and causing over
loss in bidirectional power follow up motor and
(d) Lock nut which holds worm in place on "follow up"
gear train backed off, thus throwing the gears out of line. Tem-
porary repairs by ship's force.

4. Forward bellson unit flooded out, due to fact that
casing plugs were not installed water tight. Repairs made by
ship's force.

ENCLOSURE (A)
[HANDWRITTEN: -42-]

— page 26 —
The following is a list of common English words that start with the letter "A". This list is not exhaustive but aims to provide a comprehensive selection of words across various categories and frequencies of use.

**Common Nouns:**
*   Apple
*   Animal
*   Area
*   Art
*   Age
*   Air
*   Arm
*   Award
*   Action
*   Advice
*   Ability
*   Address
*   Airport
*   Album
*   America
*   Amount
*   Angle
*   Answer
*   Anxiety
*   Apartment
*   Apology
*   Appearance
*   Appetite
*   Application
*   Appointment
*   Approach
*   Approval
*   Argument
*   Army
*   Arrangement
*   Arrival
*   Arrow
*   Article
*   Artist
*   Ash
*   Aspect
*   Assistance
*   Assumption
*   Atmosphere
*   Attempt
*   Attention
*   Attitude
*   Audience
*   Author
*   Authority
*   Average
*   Awareness

**Common Verbs:**
*   Ask
*   Allow
*   Add
*   Agree
*   Achieve
*   Act
*   Adapt
*   Adjust
*   Admire
*   Admit
*   Adopt
*   Advance
*   Advertise
*   Advise
*   Affect
*   Afford
*   Aim
*   Alert

— page 27 —
CONFIDENTIAL
Subject: U.S.S. TI OSA (SS283) - Report of Seventh War Patrol.

(L) RADIO

<u>450 KC's</u>, area frequency. No transmissions were heard

NPI was guarded continuously, except from 1000-2000 Zebra, when we
shifted to 4155 kc's. From 1100 - 2000 Zebra, 9090 kc's gave
the best reception. At all other times 14390 kc's gave the best re-
ception. All lettered serials were received.

NNN, Naval Air Group, Chungking, China, on the frequency of 4155
kc's, was guarded from 1000-2000 Zebra, from June 21 - July 10.
During that period reception was excellent, with a signal strength
of five. No Jap interference was encountered.

The messages received, with two exceptions, were easily
decoded. On July third, two messages were received with "JF" as
the key list indicator. We did not have the "JF" list aboard.
Two messages were received, one on July eleventh and one on July
thirteenth, both of which failed to break even though we tried every
trick we knew.

It is firmly believed that NNN should be further instructed
as to what information should be contained in its messages. The
majority of dispatches received just gave shipping at a designated
latitude and longitude at a specified time. By the time we received
the message it would be a few hours old, and due to its incomplete-
ness, would be of no value, even though we were in the near vicinity.
Nav Air Group should give in every message, if possible, the position,
course and speed (estimated, if necessary) and the number and type of
ships. If the aviators are not able to ascertain the speed, tell
us the type of ships and we can use this information to estimate
a speed. NNN was guarded from 0400 - 0500 Zebra (12465 kc's), the
only two days we were on the surface, in accordance with Comsubpac's
July 060729 dispatch. Although one message is supposed to be sent
daily at this time, nothing was received on this frequency. However,
with more air patrols over this area, and by sending the complete
information, NNN would prove to be an invaluable circuit.

In addition to NPI and NNN, a wolfpack frequency (204 kc's voice)
was guarded continuously from June twenty-third to July fifteenth.
All transmissions received were of signal strength five. Comparing
this patrol's wolfpack communications with our previous one, it
seems that voice is not as satisfactory as keying. All voice
transmissions that were made were spoken too fast. The importance
of speaking slowly cannot be overemphasized. The coordinated attack
code, itself, was not as efficient as the code previously used.
It was not as complete, flexible, or adaptable.

ENCLOSURE (A)

[HANDWRITTEN: -44-]

— page 32 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Seventh War Patrol
(O) DENSITY LAYERS:

Density layers in general, were variable. Most gradients
were negative, with few sharp breaks recorded. A few isothermal
lines were recorded to depths of a 100 feet. Only one positive
gradient was noted, which existed from the surface to 100 feet.

The bathythermograph, itself, could be improved by making
small scale cards, (ie, larger cards) available. Changes in the
cards now used, are difficult to read, usually resulting in an
estimated reading. This is especially true in regard to depth
readings.

We could not obtain the correct cards for our contraction due
to pressure, which is 1500 pounds per 100 feet. Therefore, the
cards we used were 2,000 lbs/100 feet. Cards having different
diving rules should be made obtainable to the submarine undergoing
refit at the advanced bases.

The following table shows the notable gradients, and their
positions, found on this patrol:
          Time Lat. Long. 1st         2nd         3rd
Date GCT  N.   E.   Grad. Depth Grad Depth Grad. Depth
13June 0122 29-34 150-57 Iso 0-40  -4   40-60  -1   60-140
14 "   1909 29-26 140-22 -7   30-360
15 "   0355 24-45 139-59 -2   30-120
15 "   2233 29-38 136-24 -1   30-130
16 "   0055 29-38 136-00 Iso 30-120
16 "   0410 29-37 135-24 -2   30-120
18 "   0520 33-19 127-16 -1   30-60  -7   60-100
21 "   0800 32-35 127-36 1    30-100
29 "   2100 34-10 124-50 -6   30-40 Iso 40-60  -8   60-75
1 July 2100 33-56 127-39 Iso 40-90 -10  90-120 1.5  120-140
3 "n   1540 32-23 128-50 -16  30-380
3 ""   1747 31-52 128-51 Iso 30-60 -3   60-100
9 "    1102 32-32 127-36 -14  30-140
10 "   0345 32-12 127-00 1.5  30-60 -15  60-140
15 "   0800 30-31 129-08 34-  30-90 Iso 90-120

ENCLOSURE (A)

[HANDWRITTEN: -49-]

— page 35 —
SUBMARINE DIVISION FORTY-FOUR

                                                                Care of Fleet Post Office,
                                                                San Francisco, California.
FB5-44/A16-3                                                    31 July 1944.

Serial: ( 0-69 )

C-O-N-F-I-D-E-N-T-I-A-L

FIRST ENDORSEMENT to
U.S.S. TINOSA Seventh
War Patrol Report.

From:       The Commander Submarine Division FORTY-FOUR.
To :        The Commander-in-Chief, U.S. Fleet.
Via :  (1)  The Commander Submarine Squadron FOUR.
       (2)  The Commander Submarine Force, PACIFIC FLEET.
       (3)  The Commander-in-Chief, PACIFIC FLEET.

Subject:    U.S.S. TINOSA Seventh War Patrol - comments on.

1. The seventh war patrol of the TINOSA was the third for the
commanding officer. The patrol extended over a period of fifty-four days, of which
thirty-two were spent in the area.

2. The following torpedo attacks were made:

       (a) Attack No. 1. Two small AOs in convoy with an AK and two DD escorts.
Six torpedoes were fired and all missed the target probably due to fire control
errors. No damage was inflicted.

       (b) Attack No. 2. SUWA MARU (large AP), TAIHOKU MARU (large AK) in
convoy with another AK, an AO, one DD, one tug and four smaller escorts. Six
torpedoes were fired making two hits in the AP and three hits in the AK. Both
ships were sunk.

       (c) The TINOSA sank by gunfire the following vessels:

           1 - 400 ton, three-masted sailing vessel, length 150 feet.

           1 - 50 ton diesel-powered fishing Sampan, length 75 feet.

           1 - 100 ton diesel powered, two-masted trawler, length 90 feet.

3. Enemy submarines were contacted and because of the alertness of the
lookouts and officer of the deck, the TINOSA was able to change course and use
evasive tactics.

4. The Japanese are very active in anti-submarine activities in this
area. Apparently there are continual air patrols. The commanding officer was very
aggressive and persisted in his attacks under the existing enemy anti-submarine
activity.

                                                                - 1 -

— page 36 —
SUBMARINE DIVISION FORTY-FOUR

FB5-44/A16-3
Serial: ( 0-69 )
C-O-N-F-I-D-E-N-T-I-A-L
Subject: U.S.S. TINOSA Seventh War Patrol - comments on.

Care of Fleet Post Office
San Francisco, California
31 July 1944.

5. The small bombs are apparently used for sonic purposes. The same
type of bomb was experienced by the PINTADO after a depth charge attack. The
enemy was trying to relocate the submarine.

6. The health and morale of the crew on arrival were excellent.

The TINOSA is enroute to Mare Island for regular navy yard
overhaul where all the machinery defects and damage will be corrected.

7. The commanding officer, officer and crew are to be congratulated
on the aggressive and successful patrol and inflicting serious damage on the enemy.

[SIGNATURE: L. N. Blair]
L. N. BLAIR.

— page 37 —
FC5-4/A16-3
Serial 0287

CONFIDENTIAL

SECOND ENDORSEMENT to
U.S.S. TINOSA Seventh
War Patrol Report.

From: The Commander Submarine Squadron FOUR.
To : The Commander-in-Chief, U. S. Fleet.
Via : (1) The Commander Submarine Force, Pacific Fleet.
(2) The Commander-in-Chief, Pacific Fleet.

Subject: U.S.S. TINOSA Seventh War Patrol - comments on.

1. Forwarded, concurring in the remarks of Commander
Submarine Division FORTY-FOUR, who has thoroughly commented on
this excellent patrol.

2. The commanding officer, officers and crew of the
TINOSA are congratulated on the success of another aggressive
patrol conducted in the face of strong and persistent anti-sub-
marine measures.

SUBMARINE SQUADRON FOUR

Fleet Post Office,
San Francisco, Calif.,
2 August 1944.
11/jsk

[SIGNATURE: C. F. ERICK]

— page 38 —
[STAMP: 8 03610]
SUBMARINE FORCE, PACIFIC FLEET hch
FF12-10/A16-3(15)/(16)
Care of Fleet Post Office,
Serial 01632 San Francisco, California.
6 August 1944.
CONFIDENTIAL [HANDWRITTEN: 8/29/47]
[HANDWRITTEN: gf]
THIRD ENDORSEMENT to NOTE: THIS REPORT WILL BE
TINOSA Report of DESTROYED PRIOR TO
Seventh War Pat. ENTERING PATROL AREA.

COMSUBSPAC PATROL REPORT NO. 490.
U.S.S. TINOSA - SEVENTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To : The Commander-in-Chief, United States Fleet.
Via : The Commander-in-Chief, U. S. Pacific Fleet.

Subject: U.S.S. TINOSA (SS283) - Report of Seventh War
Patrol. (7 June to 30 July 1944).

1. The seventh war patrol of the TINOSA was con-
ducted in the East China Sea. The TINOSA was one of three sub-
marines forming a group designated to work in adjacent areas
in order to pass contacts from one to another.

2. This patrol was particularly outstanding in
torpedo and gunnery performance, excellent area coverage in
spite of enemy air activity, and offensive spirit. The TINOSA
conducted two torpedo attacks and three gun attacks. The
torpedo attack on the night of 3 July was especially well
planned and conducted with excellent results.

3. The large percentage of submarine contacts
made by the TINOSA while in area is of note and indicates a
possible use of Japanese submarines for anti-submarine war-
fare.

4. This patrol is designated as "Successful" for
Combat Insignia Award.

5. The Commander Submarine Force, Pacific Fleet,
congratulates the Commanding Officer, officers and crew for
this aggressive and outstanding war patrol. The TINOSA is
credited with having inflicted the following damage upon the
enemy:

- 1 -

[STAMP: EXTRA - ORIGINAL]
[STAMP: SORG. MICRO]
[STAMP: PHOTO-LAB OP-16]
[STAMP: RETURN TO F-4253]

— page 39 —
SUBMARINE FORCE, PACIFIC FLEET hch
Care of Fleet Post Office,
San Francisco, California,
6 August 1944.

FF12-10/A16-3(15)/(16)

Serial 01632

CONFIDENTIAL

THIRD ENDORSEMENT to
TINOSA Report of
Seventh War Patrol.

NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.

COMSUBSPAC PATROL REPORT NO. 490.
U.S.S. TINOSA - SEVENTH WAR PATROL.

Subject: U.S.S. TINOSA (SS283) - Report of Seventh War
Patrol. (7 June to 30 July 1944).

— page 40 —
[STAMP: DECLASSIFIED]
CONFIDENTIAL
SS283/A16

U.S.S. TINOSA (SS283)
c/o Fleet Post Office,
[HANDWRITTEN: DECLASSIFIED ART. 0445, OPNAVINST 5510.1C] San Francisco, California,
Serial: 02 [HANDWRITTEN: 6/20/77] DATE 30 January, 1945.
BY [HANDWRITTEN: M.A. (signature)]

From: The Commanding Officer.
To : The Commander in Chief, United States Fleet.
Via : Official Channels.

Subject: 'U.S.S. TINOSA (SS283) - report of EIGHTH War
Patrol.

Enclosure: (A) Subject report.
(B) Track Charts(COMSUBSPAC only).

1. Enclosure (A) covering the EIGHTH War Patrol of
this vessel conducted in the NANSEI SHOTO - FORMOSA areas
during the period 4 December, 1944 to 30 January, 1945 is
forwarded herewith.

R.C. LATHAM

[HANDWRITTEN: FILMED]
[HANDWRITTEN: 106922]

— page 41 —
U.S.S. TINOSA (SS283)

CONFIDENTIAL
(A) PROLOGUE

     Arrived U.S. Naval Drydocks, Hunters Point, California,
from Seventh War Patrol on 7 August, 1944. Commenced major over-
haul. Among the important items of work accomplished were:

          Installation of six foot extension on SJ radar.
          Installation of 5"/25 cal. deck gun forward.
          Installation of 40MM gun on bridge deck aft.
          Installation of boiler type manhole covers at bottom
          end of all access hatches.
          Rerouting of electric cables from conning tower to con-
          trol room inside lower conning tower hatch trunk to keep
          cables inside pressure hull.
          Installation of Gould type centrifugal trim pump.
          Extensive alterations to Wardroom Country for increased
          accomodations.
          Installation of DRT in conning tower.
          Relocation of QB sonar head topside on main deck.
          Installation of FM sonar unit in old QB location.

     On 13 September, 1944, Lieutenant-Commander R.C. LATHAM,
U.S. Navy, relieved Commander D.F. WEISS, U.S. Navy, as
Commanding Officer.

     Completed overhaul on 23 October, 1944. Sound tested and
depermed.

     Conducted special tests at San Diego, California from
27 October, 1944 to 6 November, 1944.

     Departed San Diego, California on 7 November, 1944, and
arrived Pearl Harbor, T.H., on 14 November, 1944.

     Completed voyage repairs from 15 to 18 November, 1944.

     Completed nine days training from 19-27 November, 1944,
which included firing six exercise torpedoes, cavitation tests,
radar radiation pattern tests, practice approaches, and two
night underway exercises.

     Conducted special tests from 29 November, 1944, to 1
December, 1944, and completed final loading on 2 and 3 December,
1944. Carrying 22 MK 18-1 torpedoes, 16 forward; 6 aft.

(B) NARRATIVE

     4 December, 1944

     1330(VW) Underway from Submarine Base, Pearl Harbor, T.H., in
               accordance with CTF 17 OpOrd 400-44.
     1430(VW) Joined escort U.S.S. PC-603, enroute Midway.
     2100(VW) Released escort.

-1-
ENCLOSURE (A)

— page 42 —
U.S.S. TINOSA (SS283)
CONFIDENTIAL

5-7 December, 1944
Conducting deep dive daily at dawn, daily drills and exer-
cises. Fired all guns.

8 December, 1944.
0632(Y) Made visual contact with two plane escort.
0917(Y) Moored Midway. Remained overnight to complete repairs to
leaky SJ mast. Topped off fuel and lube.

9 December, 1944
0800(Y) Underway from Midway in company with two plane escort.
0900(Y) Submerged for short trim dive.
1000(Y) Surfaced.
1100(Y) Released plane escort.

10 December, 1944
Crossed 180th meridian. This date omitted from calendar.

11 December, 1944.
0625(M) Submerged.
0648(M) Surfaced. Conducted fire control problems and drills.
Fired deck gun.

12 December, 1944.
0648(L) Submerged.
0733(L) Surfaced.
0800(L) Barometer dropped to 29.72. Sea picking up. Wind about 40
knots, N.W.
1355(L) Forced to slow to 8 knots.
1400(L) to
1600(L) Took two green ones over bridge, received about one foot
of water in conning tower. Port lookout knocked out temp-
orarily. 240 volt ground on drain pump. Slightly damp, but
no other troubles.
2000(L) Made good 7.25 knots since 1200. Drain pump in commission.

13 December, 1944.
0612(L) Submerged.
0647(L) Surfaced.
0800(L) Wind and sea abating. Barometer back to 30.14. Making normal
two engine speed.

14 December, 1944.
0640(L) Submerged.

-2- ENCLOSURE (A)

— page 43 —
U.S.S. TINOSA (SS283)

CONFIDENTIAL

14 December, 1944 (Cont'd)

0714(L) Surfaced.
1109(L) Slowed because of solid water over bridge due to heavy seas.
1700(L) Resumed normal two engine speed.

15 December, 1944

0230(L) to
0330(L) Detected shipborne radar on APR 7 on 3100 megacycles. No
          interference on SJ. Signals were very faint indicating long
          range, bearing 027°T from Lat.30-03.5N, Long 157-38.5E.
          Contact with U.S.S. TREPANG was expected.
0650(L) Submerged.
0721(L) Surfaced.
1752(K) Radar interference on SJ. Exchanged recognition and calls
          with U.S.S. TREPANG, and also information on this mornings
          APR 7 contact. No range on sighting. Lat. 29-56N., Long
          154-00E.
          Ship contact #1.

16 December, 1944

0610(K) Submerged. Remaining submerged to replace bent depth setting
          spindle on #1 torpedo tube.
1100(K) Surfaced. New depth setting spindle installed on #1 torpedo
          tube.
2145(K) APR 1 received saturation strength radar signal at 600 me-
          gacycles. Low overcast, black, and rough. Nothing sighted.
          We are using SJ radar only, sweeping every five minutes.
2343(K) APR picked up signal on 300 megacycles.

17 December, 1944

0335(K) WAGNER, C.H.Jr., TM3c, U.S.N.R., washed off starboard high
          lookout station and landed on main deck. All stop. Wagner
          made his way back to conning tower ladder when again swept
          away, this time hanging up on life line. Made his way to
          safety by eager hands. Examined by pharmacists mate and
          discovered to have no injuries or bruises of any nature.
          Resumed laborious progress at full on one engine.
0634(K) Submerged.
0739(K) Surfaced.
1200(K) Averaged 9.3 knots last 24 hours.

18 December, 1944

0653(K) Submerged.
0736(K) Surfaced.
1130(I) Sank possible mine or buoy with 20MM, 50 cal and small arms.

-3-
ENCLOSURE (A)

— page 44 —
DENTIAL                               U.S.S. TINOSA (S
                                18 December, 1944 (Cont'd)

1130(I) It was a black sphere 3 ft.
        inch square access plate bolt
        effusion of bubbles. Similia
        Identification Manual. Lat. 2°
1145(I) Sighted "RUFE", bearing 240°
1148(I) A/C contact #1
1241(I) Submerged with RUFE at seven
1518(I) A/C #2
1520(I) A/C #2. SD contact on 160 megacyc
        Cloudy. Nothing sighted. Dic
2114(I) Slowed to 5 knots. Commence

                                19 December, 1944.

0050(I) Completed conversion of #4 FBT, a wet cold job. Blanks
        in 10# blow could not be moved, so turbo blow to #4 is o
0632(I) Submerged.
0711(I) Surfaced. #4 FBT is well flushed out. No trace of oil sli

                                20 December, 1944

0629(I) Submerged.
0707(I) Surfaced. Our track will pass within 40 miles of KITA DAITO
        JIMA. Visibility now is variable 5 to 10 miles, ceiling 1000
        feet, low flying scud. Decided to detour slightly south
        and conduct submerged reconnaissance
1130(I) Sighted KITA DAITO JIMA, bearing 219°T, 16 miles. Detected
        island radar on 160 Mcs.
1208(I) Submerged at range of 10 miles.
        Passed 1½ miles west of KITA DAITO JIMA on southerly course
        and continued south passing 1 mile west of MINAMI DAITO
        JIMA. The charts are accurate and good fixes were obtained.
        Landmarks are as described. The phosphate plant on the north
        island was busily smoking. The south island appeared in-
        active. No shipping was present at any of the five landing
        places on these two islands. A force five sea from the north-
        west was pounding each landing and sending spray 100 ft.
        into the air at all landings except the southernmost one
        on MINAMI DAITO JIMA. The heavy swell made plenty of white
        water here. No aircraft activity was noted. These islands
        definitely have radar on 102 Mcs., and 160 Mcs. Currents
        did not conform to the chart. See section on currents. No
        patrol vessels were present. Rough seas and haze spoiled
        any chances for gun action or photography.
1800(I) Surfaced at range of 3½ miles from MINAMI DAITO JIMA, course
        272°T. 160 Mc radar promptly steadied on us and apparently
        tracked us out. 102 Mc radar was intermittent. Changed
        course to 350°T, so he can track us north if he wishes.
2000(I) Radar appears weak now so came to 268°T. These seas will
        keep us from attaining a position south of OKINAWA JIMA for
        tomorrow as I had planned. It seems like a good opportunity
        to conduct a surface patrol southeast of that island, to

-4-
                                                                ENCLOSURE (A)

— page 45 —
U.S.S. TINOSA (SS283)

CONFIDENTIAL

18 December, 1944 (Cont'd)

1130(I) It was a black sphere 3 ft. in diam., no horns, about an 8
          inch square access plate bolted on, and sank with a great
          effusion of bubbles. Similiar to type 121, page 3, Mine
          Identification Manual. Lat.29-07N, Long. 141-39E.
1145(I) Sighted "RUFE", bearing 240⁰T, distance about 8 miles.
          A/C contact #1
1148(I) Submerged with RUFE at seven miles closing slowly.
1241(I) Surfaced.
1518(I) APR 1 contact on 160 megacycles, at half saturation.
1520(I) A/C #2. SD contact at 6 miles, opened rapidly to 10.
          Cloudy. Nothing sighted. Did not dive.
2114(I) Slowed to 5 knots. Commenced converting #4 FBT to MBT.

19 December, 1944.

0050(I) Completed conversion of #4 FBT; a wet cold job. Blanks
          in 10# blow could not be moved, so turbo blow to #4 is out.
0632(I) Submerged.
0711(I) Surfaced. #4 FBT is well flushed out. No trace of oil slick.

20 December, 1944

0629(I) Submerged.
0707(I) Surfaced. Our track will pass within 40 miles of KITA DAITO
          JIMA. Visibility now is variable 5 to 10 miles, ceiling 1000
          feet, low flying scud. Decided to detour slightly south
          and conduct submerged reconnaissance.
1130(I) Sighted KITA DAITO JIMA, bearing 219⁰T, 16 miles. Detected
          island radar on 160 Mcs.
1208(I) Submerged at range of 10 miles.
          Passed 1½ miles west of KITA DAITO JIMA on southerly course
          and continued south passing 1 mile west of MINAMI DAITO
          JIMA. The charts are accurate and good fixes were obtained.
          Landmarks are as described. The phosphate plant on the north
          island was busily smoking. The south island appeared in-
          active. No shipping was present at any of the five landing
          places on these two islands. A force five sea from the north-
          west was pounding each landing and sending spray 100 ft.
          into the air at all landings except the southernmost one
          on MINAMI DAITO JIMA. The heavy swell made plenty of white
          water here. No aircraft activity was noted. These islands
          definitely have radar on 102 Mcs. and 160 Mcs. Currents
          did not conform to the chart. See section on currents. No
          patrol vessels were present. Rough seas and haze spoiled
          any chances for gun action or photography.
1800(I) Surfaced at range of 3½ miles from MINAMI DAITO JIMA, course
          272⁰T. 160 Mc radar promptly steadied on us and apparently
          tracked us out. 102 Mc radar was intermittent. Changed
          course to 350⁰T, so he can track us north if he wishes.
2000(I) Radar appears weak now so came to 268⁰T. These seas will
          keep us from attaining a position south of OKINAWA JIMA for
          tomorrow as I had planned. It seems like a good opportunity
          to conduct a surface patrol southeast of that island, to

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ENCLOSURE (A)

— page 46 —
U.S.S. TINOSA (SS283)

CONFIDENTIAL
2000(I) (Cont'd)
cover possible traffic offshore to the east of NANSEI SHOTO.
I expect the area between NANSEI SHOTO and FORMOSA to be
the most productive, so my plan is to get there soon,
covering close in along the eastern side of NANSEI SHOTO
enroute.

21 December, 1944

0005(I) Entered assigned area.
0641(I) Submerged.
0750(I) Surfaced.
1000(I) Sighted OKINAWA JIMA bearing 314°T.
1015(I) With range to land 20 miles, commenced surface patrol
on 130°-310°T.
1205(I) Heard one loud ping on JK. Avoided.
Position Lat. 25-39N. Long.128-22E.

22 December, 1944.

0627(I) Submerged 8 miles south of OKINAWA JIMA. Covering passage
to and from NAHA.
1237(I) Commenced test covered in special report.
1345(I) Sighted "BETTY", range 8 miles over NAHA. A/C#3.
1849(I) Surfaced. Proceeding to next days station off MIYAKO JIMA.

23 December, 1944.

0550(I) Indication on 102 Mcs on APR 1, apparently radar on MIYAKO
JIMA.
0640(I) Submerged 6 miles south of MIYAKO JIMA.
1258(I) Visibility generally poor. Varying 4 to 30 miles. No traffic
of any nature. Seas fairly rough making periscope exposures
poor, so surfaced and commenced surface patrol along is-
land chain to westward.
1555(I) Sighted ISHIGAKI JIMA, bearing 300°T, 18 miles. Various ra-
dar signals detected on APR 1 during afternoon.
1852(I) 147 Mc signal on APR 1 at saturation. Believed this to be
a radar equipped plane, as he seemed to search and focus
on us. Remained steady on, signal increasing from moderate
to saturation in 7 minutes.
Submerged.
1915(I) Came to 35 feet to check with APR 1. 147 Mc signal again
sought us out and steadied on, increasing from strong to
saturation in 3 minutes. Went back down.
1933(I) This time determined to check APR 1, with SD, but APR all
clear, so left SD secured as usual. Surfaced.

24 December, 1944

0639(I) Submerged, in passage between IRIOMOTE JIMA and YONAKUNI
JIMA.

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ENCLOSURE (A)

— page 47 —
U.S.S. TINOSA (SS283)

CONFIDENTIAL
0639(I) (Cont'd)
Headed in to investigate anchorage on west side of IRO-
MOTE JIMA.
0920(I) Sighted sampan headed west, closest range about 8000 yards.
0948(I) Sighted second sampan headed west, closest range about
8000 yards.
1047(I) A/C#4. Sighted "ZEKE", range 6 miles on westerly course.
1210(I) Broached about 4 miles west of FUNUKE KO and observed this
anchorage and FUNUKE KITA WAN. Could see no ships.
1514(I) S/C#2 sighted tops of radio equipped sampan bearing 0480T,
6 miles. Came to normal approach course to test FM sonar.
Could not close closer than 8000 yards.
1800(H) Surfaced. Proceeding towards coast of FORMOSA.

25 December, 1944
CHRISTMAS.
0615(H) Submerged 4 miles east of FORMOSA just north of SASENDAI
LIGHT which is not burning; working north along coast.
0957(H) Sighted sampan on northerly course close to beach. Closed
beach to two miles. This was the first of several sampans.
1129(H) A/C #5. Sighted "BETTY", patrolling south along coast, dis-
tance 2 miles.
1844(H) Surfaced. Patrolling north 7-10 miles off coast.

26 December, 1944
0102(H) Submerged with A.R 1 at saturation, 100 Mc. Am quite sure,
now, that this was land based radar. Had either 100 Mc or
147 Mc radar at saturation remainder of night.
0135(H) Surfaced.
0539(H) Submerged northeast of FORMOSA, in vicinity of U.S.S.
BING's contacts.
Broached at frequent intervals for radar fix and better
view.
1819(H) Surfaced.

27 December, 1944
0611(H) Submerged northeast of FORMOSA.
1252(H) A/C #6. Sighted "TESS", through periscope, range 3 miles.
1828(H) Surfaced.

28 December, 1944
0601(H) Submerged west of IRIOMOTE JIMA.
0949(H) A/C #7. Sighted unidentified plane through periscope.
1355(H) Sighted one small sampan on easterly course. No activity
observed in FUNUKE KO.
1824(H) Surfaced.

29 December, 1944
0533(H) Submerged. Patrolling 1 to 2 miles off FORMOSA. coast just

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— page 48 —
U.S.S. TINOSA (SS263)

CONFIDENTIAL
0533(H) (Cont'd)
        north of SASENDI LIGHT.
. 1455(H) Sighted empty sampan, course south. Sampans seem to be
        loaded when on northerly course.
. 1845(H) Surfaced. Full moon, overcast, but bright. Patrolling
        ten miles off coast of FORMOSA.

30 December, 1944
. 0542(H) Submerged. Patrolling 1-2 miles off coast.
. 0649(H) Sighted sampan close to shore, course south.
. 1400(H) Inadvertently broached to 42 feet.
. 1454(H) A/C #8. Sighted "NICK", distance 3 miles, headed south
        along coast.
. 1837(H) Surfaced.
. 2000(H) Commenced clearing area in accordance with COMSUBSPAC
        despatch orders.

31 December, 1944.
. 0300(H) Broadcast TINOSA first to COMSUBSPAC. Could not establish
        communications.
. 0625(H) Sighted HADERUM JIMA bearing 330°T, 20 miles.
. 2000(H) Received COMSUBSPAC despatch showing he did not get our
        first.

1 January, 1945
0010(H) Sent TINOSA second to COMSUBSPAC. Could not contact NPM.
        Radio Perth heard us strength 2. Received authenticated
        receipt from Radio MAKIN who heard us strength 4.
0546(H) Submerged.
0645(H) Surfaced.
1405(I) Cleared area. Zero ground located inside antennae lead-in
        trunk.
2100(I) Proceeding to new area in accordance with COMSUBSPAC dir-
        ective.

2 January, 1945.
0632(I) Submerged.
0709(I) Surfaced.

3 January, 1945
0632(I) Submerged.
0707(I) Surfaced.
0814(I) Sighted SUMANOSE SHIMA bearing 315°T, distance 50 miles.
1020(I) A/C #9. Sighted unknowntype aircraft, range about 1 mile,
        elevation 80°, towards sun. Submerged.
1205(I) A/C#10. Sighted "JILL", through periscope, bearing 175°T,
        8 miles.
1550(I) Surfaced in rain squall.
1630(I) Weather overcast but clear. Proceeding on surface on south-
        -7-
        ENCLOSURE (A)

— page 49 —
U.S.S. TINOSA (SS283)
CONFIDENTIAL

1630(I) (Cont'd)
          Westerly course between AMAMI O SHIMA and TAKARA JIMA.
1900(I) Entered new area.
2100(I) Passed through between TAKARA JIMA and YOKOATE SHIMA.
          APR 1 had 155 Mc signal at saturation. Were amazed to
          have been on the surface since 1550 in this area with
          no contacts of any sort.

4 January, 1945.

0030(I) Decoded COMSUBSPAC despatch requesting amplification
          TINOSA second.
0639(I) Submerged off GAJA SHIMA.
1840(I) Surfaced.
1745(I) Exchanged calls with U.S.S. PIRANHA on SJ. S/C#3.
2100(I) Sent TINOSA third to COMSUBSPAC.

5 January, 1945

0655(I) Submerged.
0740(I) Surfaced.
1017(I) A/C #11. Sighted "PETE", coming in, range 4 miles. Sub-
          merged. Believe we were sighted.
1127(I) Surfaced.
1218(I) Signal on APR 1 at 158 Mcs, searching. Expect "PETE"
          got some help.
1318(I) A/C#12. Sighted "FRANCES" crossing astern, range 4 miles.
          Submerged.
1837(I) Surfaced.
2300(I) Received COMSUBSPAC despatch designating new area. Proceed-
          ing to new area.

6 January, 1945.

0640(I) Submerged 9 miles east of TORI SHIMA.
1838(I) Surfaced. APR 1 had 147 Mcs at saturation immediately.
          This appeared to be land based radar on OKINOYERABU JIMA.

7 January, 1945

0100(I) Decoded instructions from COMSUBSPAC for next few days of
          patrol.
0213(I) Submerged and conducted exercises which are subject of a
          special report.
0353(I) Surfaced.
0620(I) A/C #13. Sighted aircraft with running lights burning.
          Submerged four miles north of IYE SHIMA.
0936(I) S/C #4. From position 1000 yards north of IYE SUIDO
          100 fathom curve, observed naval patrol vessel anchored
          in 2 fathoms just east of IYE SHIMA. He is on west edge of
          channel, is about a 70 footer, painted gray with white
          numerals on bow. Decided not to go through passage because
          of patrol.

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— page 50 —
**CONFIDENTIAL**
**U.S.S. TINOSA (SS283)**

1033(I) A/C#14. Sighted "FRANCES", through scope.
1430(I) A/C#15. Sighted "FRANCES", through scope.
1500(I) Observed IYE SUIDO until this time. Took pictures
    of IYE JIMA. Saw one sampan come from east and go in,
    and one come out and go to eastward. Because of patrol
    vessel and traffic do not believe channel is mined.
1856(I) Surfaced two miles west of IYE JIMA and commenced tests
    which lasted through 9 January, and are part of special
    report.

**8 January, 1945.**
0321(I) S/C#5. Small indication on 023°T, 10,900 yards. Came
    to 023°T and lost contact, but at
0330(I) Exchanged calls with U.S.S. PUFFER on SJ bearing about
    023°T. Opened out on course 155°T.
0629(I) Submerged. Numerous sampans sighted during day ranging
    from 50 to 200 tons. The leader of one column of three
    had a bridge amidships similar to a freighter and made
    flag hoists on entering channel to N.H. Sampan traffic
    entered and left N.H. on approximately the following
    true bearings originating at N.H.: 005, 315,285 and 242.
1100(I) Took pictures of NAYE SHIM.
1547(I) S/C#6. Sighted our first real ship. He was an empty 5000
    ton Maru moored inside harbor at N.H. We cannot get at
    him and cannot wait for his possible exit.
1618(I) Observed possible radar stations located on north and
    south sides of SENEGA SHIM.
1805(I) A/C #16. Sighted unidentified bomber over N.H.
1905(I) Surfaced. During night patrolled about 1 mile south and
    west of TONACHI SHIM and KERAMA RETTO. APR 1 has radar
    at saturation on 97 Mcs, 102 Mcs, 147 Mcs and 157 Mcs.
    Japs have radar on nearly all their islands, and it
    generally seems steady on us, but nothing ever develops.
    This was at first disconcerting, but is now routine and
    reports from APR 1 get a bored "very well" in reply.

**9 January, 1945**
0630(I) Submerged. Patrolling 1 mile off reef on east side
    OKINAWA JIMA. NAKAGUSUKU WAN and CHIMU WAN anchorages
    appear empty.
1909(I) Surfaced. APR 1 has 97 Mcs, 147 Mcs and 102 Mcs radar
    steady on at saturation.
1955(I) Completed special tests.
2100(I) Sent TINOSA fourth and fifth to COMSUBPAC.
2344(I) Interference on SJ bearing 20°T. This a feared friendly
    and was believed to be U.S.S. KETE, but could obtain no
    response to challenge on SJ.

**10 January, 1945**
0630(I) Submerged between YORON SHIM. and OKINOYERABU JIMA.

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ENCLOSURE (A).

— page 51 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)

10 January, 1945 (cont'd)

1627(I) A/C#17. Sighted two unidentified fighter planes flying
          south in formation.
1859(I) Surfaced.
2230(I) Received message from COMSUBSPAC assigning new patrol
          area. Proceeding new area.

11 January, 1945.

0637(I) Submerged for patrol off SOTSUKO ZAKI. During day two
          very small sampans rounded the point close in to beach.
          There was no other traffic.
0950(I) A/C#18. Sighted "RUFE" through periscope.
1900(I) Surfaced. Patrolled along island chain from YOKOATE JIMA
          northeastward and back during night.
1908(I) Sighted A/A searchlights in back of SOTSUKO ZAKI.

12 January, 1945

0600(I) Sighted above searchlights again.
0639(I) Submerged off NAZE KO. During day conducted exercises
          in harbor entrance, described in special report. Took
          pictures. Harbor entrance does not appear mined.
0800(I) to
1400(I) S/C #7(EC) & #8(EC). A big day - two more ships. Reached
          fair firing position but broke off attack as both ships
          are solidly aground and high out of water on rocks. #7
          is a small passenger ship similar to KAGI MARU and has a
          rusty bottom indicating she has been there an appreciable
          time. Position of #7 is Lat. 28-24N. Long. 129-30E. #8 is a
          whale factory similar to NISSIN MARU and is located at
          Lat. 28-27N. Long. 129-29.4 E. Large seas were breaking
          over this one. Both these ships were on the rocks on a lee
          shore and could only have been damaged further by torpedoes
          and not sunk. It was evident that the rocks and seas were
          doing the job effectively, so no torpedoes were wasted.
1906(I) Surfaced.

13 January, 1945

0639(I) Submerged.
0743(I) Surfaced.
1000(I) Entered new patrol area.

14 January, 1945.

0636(I) Submerged.
0735(I) Surfaced.

15 January, 1945.

0640(I) Submerged.
0740(I) Surfaced.

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ENCLOSURE (A)

— page 52 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)

16 January, 1945.

0630(I) Submerged.
0738(I) Surfaced.
2020(I) Weak interference on SJ radar.

17 January, 1945

0641(I) Submerged.
0739(I) Surfaced.
2100(I) Received COMSUBSPAC despatch orders to terminate patrol
           on 18th.

18 January, 1945

0635(I) Submerged.
0748(I) Surfaced.
2050(I) Departed area. Enroute Midway.

19 January, 1945.

0630(I) Submerged.
0718(I) Surfaced.
1235(I) A/C #19. Sighted formation of at least 35 B-29's bound
           north.
1527(I) A/C #20. Sighted 11 or more B-29's travelling singly
           headed south.

20 January, 1945.

0658(I) A/C #21. Sighted one unidentified plane, range about 14
           miles.
1059(K) A/C #22. Sighted Emily range about 4 miles. Submerged.
1146(K) Surfaced.

21 January, 1945.

           Commenced using SD radar.

22 January, 1945.

0305(K) S/C #9. Exchanged recognition and calls with USS GULLIFISH
           on SJ radar.
0632(K) Submerged for trim dive.
0708(K) Surfaced.

23-26 January, 1945.

           Enroute Midway. Conducting daily fire control problems,
           drills, and dives.

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— page 53 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)
(A)

26 January, 1945

Crossed 180th meridian, repeated this date.
0700(Y) Rendezvoused with escort planes.
0905(Y) Moored Midway, Fueled.
1500(Y) Underway for Pearl Harbor, T.H.
1544(Y) Submerged for trim div e.
1600(Y) Surfaced.

27 January, 1945

2245(Y) SJ radar interference, no contact.

30 January, 1945

0615(VW) Joined escort, PC 570.
1030 Moored Submarine Base, Pearl Harbor, T.H.

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— page 54 —
CONFIDENTIAL                                U.S.S. TINOSA (SS283)

(C) WEATHER

          Rough weather was encountered throughout this patrol.
About 85% of the patrol days, the sea was condition 4 or 5;
about 10% condition 3; and about 5% condition 2. No exception-
ally rough weather was experienced, nor were there any days
of flat calm. There were no typhoons encountered. Two mild
storms were passed through enroute to the patrol area, but
progress was never slowed below seven knots. Weather was con-
sistently rough off FORMOSA, with frequent rain squalls and
fresh to strong winds from the north. Mild temperatures were
found off FORMOSA and in the southern islands of the NANSEI
SHOTO; while cold weather was the rule in the northern is-
lands of NANSEI SHOTO, and in the open sea area southeast of
KYUSHU.

          The sky was overcast at least 70% during the entire time
spent in the assigned areas, making solo-navigation very diffi-
cult. Solid overcast was sometimes experienced for days at a
time. Parka type rainclothes were necessary for the bridge
watch during the entire patrol, due to heavy spray and fre-
quent rain squalls.

(D) TIDAL INFORMATION

          As often as not, tides and currents in the various areas
covered during this patrol were at variance with those indi-
cated on the chart and in the Japan Pilot. Due to the many
shifts of force during this patrol, it was not practicable to
compare tidal data for a given locality over any reasonable
period of time so as to properly evaluate observed deviations
from the "normal." Two days time was the most that could be
devoted to any single locality.

          Observations of tides and currents contrary to those in-
dicated in available publications are set forth for the value
they may have by comparing with other fragmentary reports.

          Currents in the vicinity of KITA DAITO JIMA and MINAMI
DAITO JIMA did not conform to those shown on the chart. No
westerly current was experienced between the islands, as was
shown on the chart and described in the Coast Pilot. North
and west of KITA DAITO JIMA, close inshore, a current of 1.1
knots toward 150°T was observed. The set between the islands
was 120°T, drift 0.5 knot. No set was experienced south and
west of MINAMI DAITO JIMA. It is probable that the currents
experienced were influenced or controlled by the prevailing
monsoon. Wind and sea were from the northwest; force 5, condi-
tion 5.

          Currents up to 1.5 knots were experienced south of OKI-
NAWA JIMA. They shifted direction continuously, and were ob-
viously tidal currents, although the distance to the closest

-13-                                ENCLOSURE (A)

— page 55 —
CONFIDENTIAL U.S.S. TINOSA (SS283)
(D) TIDAL INFORMATION (Cont'd)

reference point (NAHA) was apparently too great for accurate
prediction. The set was predominantly in the northeast quad-
rant.

The KUROSHIO was not encountered until west of HADERUMA
JIMA. East and northeast of FORMOSA, its effect was very pro-
nounced; a set and drift of 040°T, 40 miles, being not un-
common for a single day. Wind and sea were consistently
in opposition to the current during the time spent in this
area. When operating close inshore off FORMOSA, the effect
of the KUROSHIO was much reduced, and frequently no current
at all was encountered. This was particularly noted in a
section of deep water one mile offshore, 13 miles north of
SASENDAI. The hundred fathom curve projects a few miles off-
shore just south of this area and apparently diverted the
northbound KUROSHIO to seaward for a few miles, so that little
or no current was observed here. Four or five miles farther
north, the current again became strong.

North and east of SAMUCHO KAKU, FORMOSA, currents were
strong, variable, and unpredictable. Strong tidal currents
blend here with the KUROSHIO. Prevailing currents were still
northerly, but were deflected either east or west by tides.
At any distance from the tidal reference point (KIIRUN), pre-
diction of current was virtually impossible.

Currents off YONAKUNI SHIMA and IRIOMOTE JIMA were con-
trolled by the KUROSHIO and generally conformed to those
shown on the chart. Operating close inshore to IRIOMOTE JIMA,
very little current was observed.

The current off GAJA SHIMA was directly opposite to that
shown on the chart. A set of 220°T with a drift of 1 knot
was observed. This current was in direct opposition to the
wind and sea, and is for that reason doubly difficult to un-
derstand. However, the full effect of the KUROSHIO was felt
sixty miles southwest of GAJA SHIMA the following day.

One or two miles north of IE SUIDO and IE SHIMA, a south-
easterly current of about 0.4 knots was encountered. This
may have been a tidal current, but persisted throughout a
days submerged operations.

In view of the strong currents previously experienced
south of OKINAWA JIMA, strong currents as shown on the chart
were anticipated off NAHA, but none of a greater intensity
than 0.8 knots were experienced during a days operations off
NAHA and around KEISAN SHO. No tidetables for 1945 were a-
vailable to attempt prediction of the current here.

Between OKINOYERABU JIMA and YORON JIMA, a strong east-
southeasterly current of about 1.8 knots was experienced th-
roughout a full days submerged operations, during which an

-14- ENCLOSURE (A)

— page 56 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)

(D) TIDAL INFORMATION (CONT'D)

unsuccessful attempt was made to pass between these islands
from east to west.

Close inshore off NAZE KO on AMAMI O SHIMA, a south-
westerly current of about 0.8 knots was experienced. This
may have been a tidal current, but persisted throughout
4 days operations submerged. No tide tables for 1945 were
available to check this current.

(E) NAVIGATIONAL AIDS.

Of all the navigational lights observed, only one was
found to be burning. SAMUCHO KAKU light was observed burn-
ing undimmed, and with normal characteristics and period,
from a distance of twenty miles on 26 December 1944.

The following lights were observed closely enough at
night to determine that they were not burning:

NAKAGUSUKU WAN: 21-22 December 1944, and
9 January, 1945.
SAKIHA SAKI (NAHA): 8 January, 1945.
GAJA JIMA: 4 January, 1945.
SOTSUKO ZAKI: 11-12 January, 1945.
NAZE KO: 12 January, 1945.
IYE SHIMA: 7 January, 1945.
SASENDAI: 25&30 December, 1944.
BEIRON BI (KARENKO) 25-26 December, 1944.
PEITAU KAKU: 26-27 December, 1944.
SUO WAN: 26 December, 1944.

Chief navigational aid on this patrol was the SJ radar.
Due to the strong currents, continuous overcast, and fre-
quent low visibility and rainstorms, navigation would have
been difficult indeed without the SJ. Its value was apprecia-
ted each of the one night in the area that it was out of
commission. The PPI scope was invaluable in approaching the
coast of FORMOSA, where there are too many peaks to make any
one peak distinguishable on the A-scope. Valleys, mountain
ridges, and flat areas where there are no peaks all showed
up clearly on the PPI, and made possible the identification
of almost any section of the FORMOSA coastline.

Charts furnished were excellent, and, for the most part
accurate. One exception is worthy of comment. Using H.O.
chart 6132 while south of KEISE SHIMA, landmarks on OKI-
NAWA JIMA consistently cut in 300 yards north of fixes ob-
tained on KEISE SHIMA and islands of the KERAMA RETTO,
notably MAE SHIMA. Specifically these landmarks were:

-15- ENCLOSURE (A)

— page 57 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)
(E) NAVIGATIONAL AIDS (Cont'd)

SAKIHARA ZAKI light, the radio towers behind NAHA, and tan-
gents on SENEGA SHIMA. It is possible that the outlying
islands of the OKINAWA GUNTO, or OKINAWA SHIMA itself, may
be slightly displaced on this chart.

-16- ENCLOSURE (A)

— page 58 —
[STAMP: CONFIDENTIAL]
U.S.S. TINOSA (SS283)
SHIP CONTACTS.

ENCLOSURE (A)
-17-

No. | Time | Date | Lat. | Long. | Type(s) | Initial Est. | Course | Speed | How contacted. | Remarks.
: | : | : | : | : | : | Range | : | : | : | :
: | : | : | : | : | Friendly | Not | C-0 | S-0 | SJ Radar inter | Exchanged calls,weather
: | : | : | : | : | Submarine:known | 0-090 | ference. | report, greetings. No
: | : | : | : | : | USS TRE- | [UNCLEAR: 0-17] | contact nor [UNCLEAR: W]
: | : | : | : | : | PANG | [UNCLEAR: 0-300] | radar
1. | 1752(K) | 1/22/45 | 29-56.2 N | 153-18 E | Fishing | 12,000 | C-3 | S-1 | Periscope | Exchanged recognition
: | 12/15/44 | : | : | Boat | yds | S-UNK | SJ radar in- | signals. Identified as
: | : | : | :

— page 59 —
CONFIDENTIAL

U.S.S. TINOSA (SS283)
AIRCRAFT CONTACTS
(Patrol Report, Course: How Contacted, Remarks)

| No. | Time | Date | Lat | Long | Type(s) | Range | Initial | Course | How Contacted | Remarks |
|---|
| 1. | 1145 (I) | 12/18/44 | 29-18 N | 141-41 E | RUFE | 7 mi | S-180 | | Periscope | Lost contact at 10 miles. |
| 2. | 1520 (I) | 12/18/44 | 29-06 N | 141-40 E | UNK | 8 mi | C-220 | | SD | |
| 3. | 1345 (I) | 12/22/44 | 26-01.5 N | 127-37 E | BETTY | 8 mi | C-180 | | Periscope | |
| 4. | 1047 (I) | 12/24/44 | 24-23 N | 127-34 E | 2 Eng. | 6 mi | C-270 | | Periscope | |
| 5. | 1257 (I) | 12/25/44 | 24-57.8 N | 120-32 E | BETTY | 2 mi | S-150 | | Periscope | |
| 6. | 0919 (I) | 12/27/44 | 24-28.3 N | 122-09 E | TESS | 3 mi | S-200 | | Periscope | Watch along out of sight. |
| 7. | 1120 (I) | 12/28/44 | 23-27 N | 122-31 E | Unidentified | 6 mi | S-180 | | Periscope | Correction or YONAKUNI SHIMA. |
| 8. | 1500 [HANDWRITTEN: (H)] | 12/30/44 | 23-27 N | 121-34 E | NICK | 3 mi | C-000 | | Periscope | Heading South along east coast of Formosa. |
| 9. | 1020 (I) | 1/3/45 | 29-02 N | 130-07 E | Single Engine | 1 mi | S-160 | | Periscope | Plane overhead at 85° angle. |
| 10. | 1205 (I) | 1/3/45 | 29-02 N | 130-08 E | JILL | 8 mi | C-225 | | Surface | Zero angle on bow sighted. |
| 11. | 1017 [HANDWRITTEN: (H)] | 1/5/45 | 29-23 N | 128-03 E | PETE | 4 mi | C-120 | | Surface | |
| 12. | 1318 (I) | 1/5/45 | 29-12 N | 128-59 E | FRANCES | 4 mi | C-235 | | Surface | Turning toward. |
| 13. | 0619 (I) | 1/7/45 | 27-57 N | 127-57 E | Unidentified | 2½ mi | S-UNK | | Periscope | |
| 14. | 1033 (I) | 1/7/45 | 26-44 N | 127-51 E | FRANCES | 2 mi | C-100 | | Periscope | |
| 15. | 1430 | 1/7/45 | 26-47 N | 127-49 E | FRANCES | 2 mi | S-UNK | | Periscope | Banking down toward us. |
| 16. | 1805 (I) | 1/8/45 | 26-17 N | 127-37 E | Bomber | 2 mi | S-UNK | | Periscope | Field of NAHA bomber on OKINAWA SHIMA |

(G) AIRCRAFT CONTACTS

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ENCLOSURE (A)

— page 60 —
U.S.S. TINOSA (SS283)
AIRCRAFT CONTACTS

No. | Time | Date | Lat. | Long. | Type(s) | Initial Range | Course | How Contacted | Remarks
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
17. | 1627 (I) | 1/10/45 | 27-18.2N | 128-14.9 E | Unident. | 6 mi | 330 | Periscope | Two in formation fly-
    | | | | | Fighters | | | | | ing towards OKINAWA
18. | 0950 (I) | 1/11/45 | 28-10.5 N | 128-01.7 E | RUFE | 4 mi | 000 | Periscope | One in formation.
19. | 1235 (I) | 1/19/45 | 27-27.2 N | 129-10.2 E | B-29's | 12 mi | 000 | Surface | Three in formation.
20. | 1527 (I) | 1/19/45 | 28-28.2 N | 129-48.9 E | B-29's | 10 mi | C-180 | Surface | Eleven or more in widely scat-
    | | | | | | | | | tered formations.
21. | 0658 (I) | 1/20/45 | 29-35 or more | 137-18.9 E | Unidenti- | 14 mi | C-UNK | Surface | One bearing 2500T.
    | | | | | fied | | | | | Observed lost sight
    | | | | | | | | | after 5 minutes.
22. | 1059 (K) | 1/20/45 | 29-30 N | 142-30 E | EMILY | 4 mi | C-045 | Surface | Submerged.
    | | | | | | | | C-120 |

(G) AIR CRAFT CONTACTS.

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ENCLOSURE (A)

— page 61 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)

(H) ATTACK DATA

No attacks were made.

(I) MINES.

One floating mine similar to type 121, page 3 of
Mine Identification Manual was sunk by gunfire on 18
December, 1944, at LAT. 29-07 N LONG. 141-39E.

Other information on mines is covered in a special
report submitted to COMSUBSPAC.

(J) ANTI-SUBMARINE MEASURES

The single ping heard at 1205(I) on 21 December,
1944, was a doubtful submarine contact.

No other anti-submarine measures were experienced
and no evasion was conducted.

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— page 62 —
CONFIDENTIAL U.S.S. TINOSA (SS283)

(K) MAJOR DEFECTS AND DAMAGE

C and R.
Stern Plane Indicator.

While submerged in the patrol area, the locking pin on
the drive shaft from the B end pump of the stern plane tilt-
ing unit sheared. This drive shaft controls the operation of
the stern plane mechanical indicator which in turn transmits
plane angle to the electrical indicator in the control room.
As a result of this casualty all stern plane angle indication
was lost for a period of about one hour. In order to realign
the planes for the installation of a new pin it was necessary
to run the planes against the stops in "Rise" and "Dive". Re-
pairs were accomplished by ships force. It is recommended that
an auxiliary mechanical indicator be attached to the drive
shaft of the B-end so that some sort of plane indication will
always be available even when the primary indicator becomes
inoperative.

Bow Buoyancy Vent
Bow Buoyancy Vent repeatedly failed to close under hydrau-
lic power at all depths. Tests showed that 700 pounds of
hydraulic pressure was being delivered to the piston. The vent
was readily closed in hand power each time the failure occured.
Reason for failure not determined on patrol.

ENGINEERING
Piston and Liner.

#2 Main Engine was out of commission for twelve (12) hours
due to broken piston and rings in #9 lower unit. The casualty
occured 500 engine hours after last overhaul. A new piston
and new rings were installed in the old liner. No further
difficulty was experienced. The liner should be replaced in
the refit as part of normal 1500 hour over-haul of #2 main
engine. The direct cause of this casualty was not determined.

Piston & liner
Returning from the area #2 Main Engine was put out of
commission due to a cracked liner (#4) and a broken piston
and rings (#4 lower). #4 liner is out of round and "mikes"
too small for removal of the upper piston normally through the
lower half of liner. There are 823.7 engine hours on this
assembly since the last engine overhaul. This is the second
casualty to pistons and liners on #2 Main Engine since over-
haul at Hunters Point. #2 Main Engine should be given a
thorough overhaul during the coming refit.

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— page 63 —
CONFIDENTIAL U.S.S. TINOSA (SS283)

(K) BATTERY CELLS.

The sealing compound on ten (10) cells in the forward
battery showed excessive cracking. Three cells, numbers 117,
118 and 119, were spilling acid through the sealing compound
cracks. All cells were repaired by a hot soldering iron app-
lied to the cracks in the sealing compound. Hodges should
be carefully inspected during the coming refit to insure
that the battery cells are not shifting in rough weather,
causing undue strain on the cells and resulting in cracks.

ORDNANCE
Mk 18 Torpedoes

While leaving Midway Island Channel a wave broke over
the bow sending some water through the open forward torpedo
room hatch causing about two quarts of sea water to enter
the battery compartment of each of four Mk 18 torpedoes.
Quick action in draining and drying the battery compartments
eliminated all grounds. No further difficulty was experienced
with these torpedoes.

Torpedo tube depth setting spindles.
During the reloading of torpedoes, after charging,
the depth setting spindle on number one torpedo tube was
bent while attempting to engage it with the torpedo depth
spindle. Examination showed that the torpedo depth spindle
was offset from the center line. A new tube spindle was
installed with maximum flexibility assured, thus permitting
engagement with the torpedo spindle.

(L) RADIO
(a) Reception and Transmissions.

Reception of NPM was good. 9090 Kcs was received with
about the same signal strength as the old 9515 Kcs series
and with less interference.
From 1400(H) to 1600(H), 9090 Kcs was received with
signal strength 5 which decreased slightly as the day ad-
vanced. Jap broadcast station seemed to be using 6045 Kcs
and became most obnoxious at 0500(H) daily. NPM was lost on
all frequencies for an hour or two at about 0500(H). NPM press
news was greatly appreciated.
Radio Chungking was received strength five. Two of the
messages would not break. No attempt was made to transmit
to China.
Transmissions to NPM were cleared with difficulty. Of
the five messages sent from the area, the first could not
be cleared, the next one was cleared through Makin Island,
and the last three through Australia. A persistent ground
in the antenna lead-in trunk contributed to the normal
difficulties. Transmission should be easier now that Radio
Guam is back in commission. Signals on wolfpack frequenc-

-22- ENCLOSURE (A)

— page 64 —
CONFIDENTIAL U.S.S. TINOSA (SS283)

(L) RADIO (Cont'd)
The sets were heard with varying strength and through the usual
Jap transmissions. Messages were copied from SOLESMIC subs
known to be about 3000 miles away.

The following frequencies gave best results:

1800(H) to 0600(H) - 6045 Kcs S-4
1400(H) to 1800(H) - 9090 Kcs S-5
0600(H) to 1400(H) - 16,730 Kcs S-3

(b) Operating procedure.

It was noticed that shore stations were reticent to
authenticate on preliminary call-up, even when asked to
do so. "VHF9" and MAKIN would not accept our encoded task
unit designation and required the encoded ship's radio
call, in spite of authentication by us. Both of these
practices cause delays and are an aid to Jap radio de-
ception and trickery.

(c) Defects of Design and Operation

The copper tubing of the starboard antennae load-in,
in the superstructure, between the insulator on the star-
board side and the antennae trunk on the port side, should
be shielded. It is recommended that the antennae trunk
itself be extended over to the starboard side. As now con-
structed, after a few days at sea, it is impossible to
clear the low ground reading on the starboard antenna.

The APR units in the radio room should be moved to the
control room in the vicinity of the SD radar. This will pro-
vide for (a) direct communication between APR and bridge,
(b) allow the APR operator to also operate the SD radar if
desired and (c) provide space in the radio room for a second
radio operator. Relocation of the RBO to the present APR
location will provide another high frequency receiver in
the radio room if needed.

(M) RADAR
SD:
The SD radar was used only enroute to and from the area.
The performance during this time was good. Two 8014 tubes
had to be replaced and the unit retuned.

SJ:
The SJ gave very good performance throughout the patrol.
This gear was used extensively in navigating among the many
islands of the NANSEI SHOTO. The SJ was able to detect high
peaks on FORMOSA at a range estimated to be in excess of
110,000 yards. An 838 tube in the voltage regulator had to
be changed to eliminate double pulsing. The SJ radar was out

-23- ENCLOSURE (A)

— page 65 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)
(M) RADAR (CONT'D)
SJ:
of commission for tuning on the night of 10-11 January
1945.

While the TINOSA was at Hunters Point a five foot exten-
sion was put on the SJ antenna mast. It is believed that
ranges were slightly improved during this patrol, but the
extension is not recommended.

The following installations would be very desirable addi-
tions to SJ radar. (1) A range counter that would permit the
accurate reading of ranges in excess of 40,000 yards. (2) The
incorporation of some type of amplifier to permit better re-
ception of SJ interference.

APR Performance
TN-2 and TN-3 Units.

These units were manned at all times the ship was on the
surface. The majority of interceptions were from 62 to 160
megacycles. Many landbased radar units were detected as is
noted in the following tables. The only trouble encountered
with the TN unit was a bad 2x2 tube in the AN/SPA-1.

R135/APR-7:

During the patrol this unit was carried for the detection
of enemy radar in the ten centimeter region. It is desired that
more extensive tests be given this unit before definite con-
clusions are reached as to its capabilities. The APR7 contact
on 15 December, 1944, may have been from own ship, since no
other contacts were obtained.

GENERAL

The SD radar was used enroute to and from the area only,
when Jap planes were not expected. In the area the SD was kept
warmed up in a standby status to be ready for checking APR 1
contacts.

The SJ was used at night, and in low visibility, making
a careful check every five minutes. Rapid sweep and PPI
scope were used to check APR 1 contacts.

The APR7 was a dismal failure and it is suspected that this
unit never functioned properly. It was hoped that the APR 7
would detect Jap shipborne radar in the 3000 mc band at long
ranges and give a bearing, thereby leading to innumerable
contacts. The answer to this problem will revive waning sub-
marine warfare.

-24- ENCLOSURE (A)

— page 66 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)

(M) RADAR
SJ Radar Interference

Date | Bearing (T) | Lat. | Long. | Remarks
Time | | | |
12/15/44 | 290 | 29-54 N | 153-58.8E | Exchanged recog-
1752(K) | | | | nition signals
| | | | with USS TREPANG.
1/4/45 | 080 | 29-51 N | 129-05 E | Exchanged recog-
1930(I) | | | | nition signals
| | | | with USS PIRANHA.
1/7/45 | 105 | 26-38 N | 127-29 E | Did not try to
2115 | | | | establish communi-
| | | | cation.
1/8/45 | 023 | 26-20N | 127-37E | Exchanged recog-
0330(I) | | | | nition signals
| | | | with USS PUFFER.
1/9/45 | 205 | 26-28N | 128 -06E | Could get no reply
2344(I) | | | | from our challenge.
| | | | Weak interference.
1/16/45 | 143 | 29-22N | 133-57E |
2020(I) | | | |
1/22/45 | 245 | 29-24N | 152-42E | Exchanged recogni-
0305(K) | | | | tion and calls with
| | | | USS QUEENFISH.

Type 726 AY magnetron is installed in SJ.

-25-
ENCLOSURE (A)

— page 67 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)
APR 1 CONTACTS.
(M) R.D.R.
:DATE :LAT. :Pulse :Swoop:
No.:TIME :LONG :FREQ.:PRF:Width :Rate : REMARKS.
: : : :Micro :
: : : :Second:
:12/18/44:29-10 N : : : :Irre-:Came from Plane as SD
1.:1520 :140-23 E :160MC:400: 12 :gular:indicated
:12/20/44:26-5 N : : : : :Landbased. Believe to be
2.:1150 :131-27 E :102 :700: 30 :½ rpm:on OKINAWA DAITO JIMA or
: : : : :MINAMI DAITO JIMA. Pro-
: : : : :bably the latter.
:12/20/44:26-6 N : : : : :Landbased. Believe to be
3.:1134 :131-28 E :161 :450: 10 :-- :on IHEYA DAITO JIMA.
:12/21/44:25-58 N : : : : :Landbased air search
4.:0845 :128-27 E :101 :700: 50 :½ rpm:based on OKINAWA SHIMA.
:12/21/44:25-54 N : : : : :Landbased air search
5.:1043 :128-17 E : 97 :700: 40 :½rpm :based on OKINAWA SHIMA.
:12/21/44:25-57 N : : : : :
6.:1859 :127-40 E :148 :350: 12 :-- :
:12/23/44:24-33 N : : : : :Landbased air search pro-
7.:0554 :125-35 E :103 :750: 25 :½rpm :bably based on MIYAKO
: : : : :JIMA.
:12/23/44:24-27 N : : : : :Had for only four minutes.
8.:1315 :125-06 E :137 :450: 12 :-- :Strong.
:12/23/44:23-59 N : : : :Not :Reached saturation in 7
9.:1850 :124-25 E :147 :450: 12 :sweep-:minutes. Dove. Probably
: : : :ing :airborne.
:12/24/44:23-59 N : : : :Irre-:Moderate in Strength.
10.:0100 :123-32 E :153 :1000:12 :gular:
:12/24/44:24-20 N : : : : :
11.:1800 :123-25 E :145 :500 :10 :" " :
:12/25/44:23-9.5 N : : : : :Had signal for forty
12.:0635 :121-35 E :153 :500 : 8 :-- :minutes.
:12/26/44:24-08 N : : : : :
13.:0200 :122-53 E :147 :450 : 5 :Steady:Weak.
:12/26/44:24-13.5 N : : : : :" " :Probably landbased on
14.:0100 :122-54 E :100 :750 : 25 : :IRIOMOTE. Had again at
: : : : :0415 strong.
:12/26/44:24-16 N : : : : :" " :Had on APR for sometime.
15.:0220 :122-59 E :147 :450 : 5 : :Weak.
:12/26/44:24-32.5 N : : : :Irre-:Weak.
16.:0410 :122-54 E :157 :450 : 7 :gular:
:12/27/44:25-04 N : : : :Irre-:Weak to moderate. Had a-
17.:0610 :122-25 E :101 :700 : 20 :gular:gain at 1834. Probably
: : : : :landbased air search.
:12/28/44:24-17 N : : : : :" " :Weak.
18.:1935 :123-18 E :145 :450 : 12 : :
:12/29/44:23-35 N : : : :Irre-:Moderate- signal lasted
19.:2032 :121-46 E :142 :450 : 5 :gular:for six minutes.
:1-2-45 :25-36.8 N : : : : :" " :Lasted for two hours.
20.:0748 :131-45.4 E :155 :500 : 12 : :Probably landbased on
: : : : :MINAMI DAITO JIMA.

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ENCLOSURE (A)

— page 68 —
U.S.S. TINOSA (SS283) APR 1 CO T.CTS.

CONFIDENTIAL
(L) RADAR
No. :DATE     :L.T.    :FREQ. :Pulse    :Sweep: :REMARKS.
    :TIME     :LONG    :      :PRF:width  :Rate :
    :         :        :      :Micro    :     :
    :         :        :      :Second:     :

21:1-3-45 :29-6 N  :152   :900: 10   :irre- :Probably airborne. Dove
   :0650.    :130-21 E:      :         :gular::plane contact 30 min-
   :         :        :      :         :      ::utes later. Original si-
   :         :        :      :         :      ::gnal was switched on
   :         :        :      :         :      ::quickly three times.

22:1-3-45 :29-02.4 N:82    :400: 25   :"     :":Took Landbased air search.
   :1610     :129-58 E:      :         :      ::Signal went out at
   :         :        :      :         :      ::1620. Had again on the
   :         :        :      :         :      ::11th & 12th January 1945.

23:1-3-45 :29-02.4 N:155   :450:      :---   ::Took at first. At 2000 sig-
   :1600     :129-58 E:      :500: 10   :      ::nal came to saturation.
   :         :        :      :         :      ::Landbased -air search.
   :         :        :      :         :      ::Believe definitely on
   :         :        :      :         :      ::TINOSA JIM. Had indica-
   :         :        :      :         :      ::tion of lobe switching.

24:1-4-45 :29-51 N :155   :450: 10   :---   ::Took Landbased air search.
   :1900.    :129-10 E:      :         :      ::Probably may be same as ob-
   :         :        :      :         :      ::tained from TINOSA JIM.

25:1-5-45 :29-16 N :158   :500: 5    :Appear::Airborne-moderate sig-
   :1220     :128-6 E :      :         :ed only::nal. Had aircraft
   :         :        :      :         :two times::contact few minutes
   :         :        :      :         :      ::later.

26:1-6-45 :27-00 N :97    :740: 40   :½ rpm ::Landbased air search.
   :         :127-24 E:      :         :      ::Based on OKINAWA JIM. Same
   :         :        :      :         :      ::as in report No. 5. Had
   :         :        :      :         :      ::signal next three days.

27:1-6-45 :26-54 N :101   :700: 50   :½rpm  ::Landbased air search.
   :         :127-33E :      :         :      ::Based on OKINAWA JIM.
   :         :        :      :         :      ::Same as in report No.4
   :         :        :      :         :      ::Had signal next three days.

28:1-9-45 :26-11.9 N:157   :450: 7    :irre- ::Strong signal.
   :0635     :127-45 E:      :         :gular::

29:1-10-45:27-15.5 N:147   :455: 15   :"     :":Saturation.
   :1900     :128-25 E:      :         :      ::

30:1-12-45:28-48 N :156   :500: 6    :Steady::Saturation - steady.
   :0310     :129-19  :      :         :      ::

31:1-12-45:28-38 N :152   :500: 7    :"     :":Strong.
   :0420     :129-10  :      :         :      ::Took to saturation in two

32:1-12-45:28-37.9 N:155   :500: 10   :Steady::minutes. Probably air-
   :1907     :129-32.2E:      :         :      ::borne.

33:1-12-45:28-55 N :155   :450: 15   :---   ::Saturation in 3 minutes.
   :2205     :129-45.5E:      :         :      ::

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ENCLOSURE (L)

— page 69 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)
(N): SOUND GEAR AND SOUND CONDITIONS

Sound conditions throughout the patrol were
good. No marked density layers were encountered.
Considerable background noise was noted from surf
and shoals during the time spent in shallow water.

No troubles were encountered, and all sound
gear gave good performance during the entire patrol.

SOUND GEAR LISTENING RANGES
Date:             | 12/25/44 | 12/28/44 | 1/7/45   | 1/7/45
Time (Zone)       | 1430 (-8)| 1345     | 0935 (-9)| 1415
Water depth (Fathoms)| 250      | 195      | 195      |
                  |          |          |          |
                  |
SUBMARINE         |
Latitude          | 23-32N   | 24-26N   | 26-45N   |
Longitude         | 121-34E  | 123-36E  | 127-55 E |
Course            | 015      | 210      | 240      | 270
Speed             | 3        | 3        | 3        | 3
Keel depth        | 70 ft.   | 70 ft.   | 65 ft.   | 70 ft.
                  |          |          |          |
                  |
TARGET            |
Type target       | Sampan   | Sampan   | Sampan   | Sampan
Tonnage           | UNKNOWN  | UNKNOWN  | UNKNOWN  | UNKNOWN
Speed (Est)       | 6 kts    | 10 kts.  | 10 kts.  | 10 kts.
Turn count        | --       | 240      | 240      | 260
(RPM)             |          |          |          |
                  |
Type sound Equipment in | JP       | JK       | JP       | JK
use by S/M        | JK       | JP       | JK       | JP
What did sound first | Screws   | Screws   | Screws   | Screws
pick up?          |          |          |          |
In frequency band (KCS)| 17       | 17       | 17       | 17
Initial range (yds)| 7,000    | 9,000    | 10,000   | 7,000.
                  |          | Est.     |          |
Maximum range contact | 10,000   | 12,000   | Unknown  |
held (yards)      |          |          |          |

— page 70 —
CONFIDENTIAL
(O)
U.S.S. TINOSA (SS283)

DENSITY LAYERS

Out of 55 Submarine Bathythermograph cards taken on this
patrol, only fifteen showed thermal layers, nine of which were
worthy of mention. Thirty were isothermal and the remaining
twenty had very slight negative gradients from the surface to
maximum submergence. There were no positive gradients found.

The rough and overcast weather which prevailed throughout
the greater part of this patrol provided good mixing and ex-
plains the predominantly isothermal water encountered.

The cards taken which showed layers with noticeable grad-
ients were as follows:

| No. | Date | Position | Layer Data |
|---|---|---|---|
| 1 | 11 Dec.1944 | 29-31.9N | 1°negative gradient(71°to70°)from surface |
| | | 161-36.1 E | to 220'. |
| | | | 6° " " (70°to64°)from 220' to |
| | | | 300'. |
| | | | 64° from 300' to 310' |
| 2. | 13 Dec.1944 | 30-07.2N | 72° from surface to 227' |
| | | 161-30.9 E | 6°negative gradient(72°to66°)from 227' to |
| | | | 262'. |
| | | | 1° " " (66°to65°)from 262' to |
| | | | 320'. |
| 3. | 14 Dec.1944 | 30-04.0 N | 1° " " (72°to71°)from surface |
| | | 156-37.1 E | to 261'. |
| | | | 4° " " (71°to67°)from 261' to |
| | | | 270'. |
| | | | 67° from 290' to 344'. |
| 4. | 16 Dec.1944 | 29-31.4 N | 72° from surface to 260' |
| | | 146-55.8 E | 4° negative gradient(72°to68°)from 260'to |
| | | | 320'. |
| 5. | 17 Dec.1944 | 29-19.2N | 71° from surface to 300' |
| | | 142-47.8E | 4° negative gradient(71°to67°)from 300'to |
| | | | 332'. |
| 6. | 24 Dec.1944 | 23-10.5 N | 2° negative gradient(77°to75°)from surface |
| | | 121-29.4 E | to 250'. |
| | | | 3° " " (75°to72°)from 250'to |
| | | | 285'. |
| 7. | 25 Dec.1944 | 25-04.0N | 75°from surface to 240' |
| | | 122-16.3E | 4°negative gradient(75°to71°)from 240' to |
| | | | 288'. |
| 8. | 26 Dec.1944 | 25-24.3 N | 76° from surface to 130'. |
| | | 122-25.8 E | 9° neg.tive gradient(76°to67°)from 130' |
| | | | to 245'. |
| | | | 67° from 245' to 360'. |
| 9. | 29 Dec.1944 | 23-07.7 N | 74° from surface to 200'. |
| | | 121-26.0E | 10° negative gradient(74°to64°)from 200' |
| | | | to 320'. |

-29-
ENCLOSURE (..)

— page 71 —
CONFIDENTIAL U.S.S. TINOSA (SS283)

(P) HEALTH, FOOD AND HABITABILITY.

Health was good.

Food was very good. It was abundant, varied and well
prepared.

Habitability was excellent.

(Q) PERSONNEL

Number of officers on board 10
Number of enlisted men on board 77
Number of men qualified at start of patrol - - - - - 52
Number of men qualified at end of patrol - - - - - - 60
Number of men advanced in rating during patrol - - - - 6
Number of men making their first war patrol - - - - - 17

The period prior to this patrol was marked by a high person-
nel turnover. Only the third, seventh and eighth officers had made
previous patrols in this ship. 30 enlisted men were transferred prior
to the start of the patrol, and 32 men were received aboard for duty.
This large turnover was occasioned by the large number of men aboard
who had made, or thought they had made, too many patrols. The import-
ance of an orderly turnover of experienced personnel each refit can-
not be overemphasized. It has been said that there is no substitute
for experience; but experience loses much of its value when tempered
by a persecution complex growing out of being retained on board too
long as "indispensible". Ship spirit was increased markedly by the
leaven of new personnel and the elimination of experienced malcon-
tents. Operational efficiency did not suffer; on the contrary, it
improved.

School of the boat for unqualified men was held regularly
by all ships officers. Notebooks, sketches and a thorough practi-
cal examination by experienced officers were required for qualifi-
cation. The interest in qualification displayed by new men was con-
sistent and gratifying.

Advancements in rating were limited by vacancies in com-
plement.

It is recommended that the authorized complement of all
Fleet type submarines be increased by one second class gunners mate.
With the increase in submarine gun armament, it has been necessary
to carry two gunners mates on patrol to keep topside armament in
usable condition. This is a lasting condition, not a transient one;
and it is believed to be common to all Fleet submarines. With the
advent of the vacancy system of advancement, a "dead end" has been
created in front of the junior gunners mate on the ship. It is not
possible to get the best out a man when he is confronted with the
realization that no amount of application and hard work can earn
him an advancement in rating on board.

-30- ENCLOSURE (A)

— page 72 —
CONFIDENTIAL                               U.S.S. TINOSA (SS283)

(R) MILES STEAMED- FUEL USED.

                                               MILES      GALLONS
     Pearl Harbor, T.H. to Midway                1266       20,085
     Midway to Area                              2805       33,045
     In Area                                     5373       45,120
     Area to Midway                              2609       28,378
     Midway to Pearl Harbor, T.H.                1240       20,000
     TOTALS.                                     13,293     146,628

(S) DURATION.

                                               DAYS
     Pearl Harbor, T.H. to Midway                4
     Midway to Area                             11
     In Area                                    29
     Area to Midway                              9
     Midway to Pearl Harbor, T.H.                4
     Days Submerged                             15

(T) FACTORS OF ENDURANCE REMAINING.

     Torpedoes       Fuel Gallons       Provisions       Personnel
     Number.
     22              4,000              20               Indeterminate.
                                                         Patrol terminated
                                                         in accordance with
                                                         operation order.

                               -31-                               ENCLOSURE (A)

— page 73 —
[STAMP: CONFIDENTIAL]
(W) REMARKS

U.S.S. TINOSA (SS283)

The lack of contacts emphasizes the need for a radar
detector which will locate radar equipped surface craft.
Measures and countermeasures continually follow one an-
other. A good detector developed now will increase our
search area tremendously and help offset the expected im-
provement and wider use of Japanese surface search radar.

It is noteworthy that despite the recognized benefit
to morale provided by 16 mm movie entertainment, no films
were available in San Francisco, San Diego, or Pearl Harbor.
Five films were obtained in Midway and were greatly appreciated.
Upon return to Midway these films and projector were sacrificed
for ben efit of another submarine departing on patrol without
entertainment. It is doubtful whether our loss can be replaced.
Improvement in the quantity, quality, and distribution of 16mm
movie films and projectors will add its bit to maintenance of
high morale.

Morale of officers and men is excellent. This is noteworthy
in view of the especially hazardous nature of this patrol, com-
bined with the sad lack of opportunities to attack the enemy.

-32- ENCLOSURE (A)

— page 74 —
FB5-45/A16-3

Serial: 05

C-O-N-F-I-D-E-N-T-I-A-L
FIRST ENDORSEMENT to
CO TINOSA Conf. ltr.
A16 Ser. 02 of 1/30/45
Report of 8th W.P.

SUBMARINE DIVISION FORTY-FIVE

Care of Fleet Post Office,
San Francisco, California.

30 January 1945.

From: The Commander Submarine Division FORTY-FIVE.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarine Squadron FOUR.
(2) The Commander Submarine Force, PACIFIC FLEET.
(3) The Commander-in-Chief, United States PACIFIC FLEET.

Subject: U.S.S. TINOSA (SS283) - Report of EIGHTH War Patrol.

1. The EIGHTH war patrol of the U.S.S. TINOSA was conducted in the
NANSEI SHOTO - FORMOSA areas. This was the first war patrol for the new Com-
manding Officer as such. The patrol was of fifty-eight days duration.

2. The TINOSA conducted a particularly hazardous special mission.
This mission was successfully completed.

3. In addition the TINOSA made an extremely valuable reconnaissance
of various islands in the NANSEI SHOTO's. Photographs and tidal information
should be of extreme value to all concerned in future operations.

4. No torpedo attacks were made because no targets worthy of torpedo
fire were found. The lack of targets and enemy aircraft was undoubtedly due to
Admiral Halsey's many strikes in the LUZON - FORMOSA - NANSEI SHOTO areas dur-
ing this period of time. Of note is that the TINOSA saw two ships aground and
abandoned in NAZE KO. One of these, a large whale factory of the KYOKUYO MARU
class tankers, is also pictured in the 29 January copy of CINCPCA Intelligence
Bulletin.

5. The TINOSA returned from patrol in an excellent state of cleanli-
ness and fairly good material condition. Repairs will be accomplished by the
Submarine Base repair facilities.

6. The Commander Submarine Division FORTY-FIVE congratulates the Com-
manding Officer, officers, and crew for the successful performance of this
most dangerous mission and for the most thorough and complete reconnaissance
made.

[SIGNATURE: illegible]
E. W. GRENFELL.

— page 75 —
SUBMARINE SQUADRON FOUR
Fleet Post Office
San Francisco, California.
11/wft

FC5-4/A16-3
Serial: 0117
6- FEB 1945

C O N F I D E N T I A L

SECOND ENDORSEMENT to
USS TINOSA (SS283) Report
of Eighth War Patrol.

From: The Commander Submarine Squadron FOUR.
To : The Commander-in-Chief, UNITED STATES FLEET.
Via : (1) The Commander Submarine Force, PACIFIC FLEET.
(2) The Commander-in-Chief, U.S. PACIFIC FLEET.

Subject: U.S.S. TINOSA (SS283) - Report of Eighth War Patrol.

1. Forwarded, concurring in the remarks of the Com-
mander Submarine Division FORTY-FIVE.

2. The Commander Submarine Squadron FOUR heartily
congratulates the Commanding Officer, officers, and crew of the
TINOSA upon completion of this patrol and the special missions
involved therein.

[HANDWRITTEN: /s/ W. V. O'Regan]
W. V. O'REGAN.

— page 76 —
FF12-10(A)/A16-3(13) SUBMARINE FORCE, PACIFIC FLEET Ga
Serial 0170 Care of Fleet Post Office,
San Francisco, California,
CONFIDENTIAL 9 February 1945

THIRD ENDORSEMENT to 14 FEB 1945 NOTE: THIS REPORT WILL BE
TINOSA Report of DESTROYED PRIOR TO
Eighth War Patrol. ENTERING PATROL AREA.

COMSUBSPAC PATROL REPORT NO. 658
U.S.S. TINOSA - EIGHTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To : The Commander in Chief, United States Fleet.
Via : The Commander in Chief, U.S. Pacific Fleet.

Subject: U.S.S. TINOSA (SS283) - Report of Eighth War Patrol
(4 December 1944 to 30 January 1945).

1. The eighth war patrol of the TINOSA, under the command
of Commander R. C. Latham, U.S. Navy, was conducted in the Nansei
Shoto - Formosa Areas.

2. During this long, arduous patrol the TINOSA had no
opportunity to attack the enemy. She is, however, entitled to great
praise for a job well and courageously done in connection with a
special mission which she carried out. This special mission is the
subject of a special report.

3. Award of Submarine Combat Insignia for this patrol
is authorized.

4. The Commander Submarine Force, Pacific Fleet,
congratulates the commanding officer, officers, and crew of the
TINOSA for the successful accomplishment of a very important special
mission.

J. H. BROWN, Jr.,
Deputy ComSubPac.

DISTRIBUTION:
(Complete Reports)
Cominch (7)
CNO (5)
Cincpac (6)
JICPOA (1)
ADICPOA (1)
Comservpac (1)
Cinclant (1)
Comsubslant (8)
S/M School, NL (2)

(Cont'd next page) - 1 -

— page 77 —
FF12-10(A)/A16-3(16) SUBMARINE FORCE, PACIFIC FLEET Ga
Serial 0170 Care of Fleet Post Office,
San Francisco, California,
CONFIDENTIAL 9 February 1945
THIRD ENDORSEMENT to NOTE: THIS REPORT WILL BE
TINOSA Report of DESTROYED PRIOR TO
Eighth War Patrol. ENTERING PATROL AREA.

COMSUBSPAC PATROL REPORT NO. 658
U.S.S. TINOSA - EIGHTH WAR PATROL.

Subject: U.S.S. TINOSA (SS283) - Report of Eighth War Patrol
(4 December 1944 to 30 January 1945).

— page 78 —
SS283/A16
Serial: (011)
[STAMP: CONFIDENTIAL (crossed out)]
[STAMP: DECLASSIFIED]
C O N F I D E N T I A L

U.S.S. TINOSA (SS283)

Care of Fleet Post Office,
San Francisco, California,
APRIL, 1945.
[STAMP: DECLASSIFIED ONAVNINST 5510.1C]
BY [SIGNATURE: G.M.K.] DATE [HANDWRITTEN: 6/20/7]

From: The Commanding Officer:
To : The Commander-in-Chief, UNITED STATES FLEET.
Via : Official Channels.

Subject: U.S.S. TINOSA (SS283) - Report of War Patrol
number NINE.

Enclosures: (A) Subject Report.
(B) Track Chart - for Commander Submarine
Force, PACIFIC FLEET only.

1. Enclosure (A), covering the ninth war patrol
of this vessel conducted in the East China Sea during the
period 1 March, 1945 to 7 April, 1945, is forwarded herewith.

2. The Commanding Officer U.S.S. TINOSA (SS283)
was also in command of a coordinated attack group including
U.S.S. SPADEFISH (SS411) and U.S.S. TIRANTE (SS420). No
separate report is submitted for this group since special
missions assigned to the U.S.S. TINOSA and U.S.S. SPADEFISH
combined with U.S.S. TINOSA's early departure from area to
prevent the group acting as a unit.

R.C. LATHAM

[HANDWRITTEN: FILMED]
[HANDWRITTEN: 118117]

— page 80 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Ninth War Patrol.

(A) PROLOGUE.

Arrived Pearl from Eighth War Patrol on 30 January, 1945.
Underwent normal refit by Submarine Base and Submarine Divi-
sion FORTY-FIVE. Removed special extension previously carried
on SJ radar mast. Installed ST radar. The ship underwent nor-
mal training during which, five exercise torpedoes were fired.
Readiness for sea 1 March, 1945.

(B) NARRATIVE.

1 MARCH, 1945.

0900(VW) Underway for PENGUIN BANK to conduct special tests.
PC 1078 escorting.
1228(VW) Special test completed. Enroute entrance to Pearl to
disembark observers.
1426(VW) Observers left ship in retriever. Underway for SAIPAN.
PC 1078 escorting.
1955(VW) Escort, PC 1078, departed.

2 MARCH, 1945.

0722(VW) Submerged for trim dive.
0754 (VW) Surfaced.
1000(VW) S/C#1 Sighted U.S. Submarine on surface on easterly
course. Probably U.S.S. BATFISH.
1200(W) Position LAT. 20-41 N., LONG. 164-01.2W.
Conducted daily trim dives at dawn, submerging to
320 feet for bathythermograph card. Conducted daily
fire control, tracking, and emergency drills enroute
SAIPAN.

3 MARCH, 1945.

1200(X) Position LAT. 20-43.6N., LONG. 170-55.8W.

4 MARCH, 1945.

1200(X) Position LAT 20-35.9N., LONG. 177-31.8W.

5 MARCH, 1945.

Crossed 180th Meridian. This date omitted.

6 MARCH, 1945.

1200(K) Position LAT. 20-16N., LONG. 175-39-2E.

7 MARCH, 1945.

1200(L) Position LAT. 20-06.7N., LONG. 168-47.3#.

-1-

— page 81 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Ninth War Patrol.

(B) NARRATIVE(Cont'd)

7 MARCH, 1945.
1938(L) Friendly SJ radar interference. No contact. Probably
        U.S.S. HAKE, or U.S.S. PARGO.

8 MARCH, 1945.
1200 (L) Position LAT. 19-32.8N., LONG. 162-14.2E.
1623(L) Battle stations surface. Fired all guns for training.
2000(L) Sent TINOSA first to CTG. 17.7 requesting rendezvous.

9 MARCH, 1945.
1200(K) Position LAT. 18-54.8N., LONG. 155-31.3E.
2252(K) Friendly SJ radar interference. No contact. Probably
        U.S.S. SCABBARDFISH.

10 MARCH, 1945.
1200(K) Position LAT. 17-26.9N., LONG. 149-15.2E.
1850(K) A/C #1. Submerged upon SD contact closing rapidly to
        3 miles. No IFF.
1913(K) Surfaced.
2015(K) A/C#2. Submerged on SD contact closing rapidly to 3
        miles. No IFF.
2045(K) Surfaced.

11 MARCH, 1945.
0147(K) Passed SARIGAN ISLAND, M.I., abeam to starboard dis-
        tance 12 miles.
0411(K) A/C#3.Submerged on SD contact closing rapidly to 3
        miles. No IFF. The above 3 aircraft contacts were un-
        doubtedly friendly, but they didn't act so.
0419(K) Surfaced.
0445(K) Rendezvoused with escort, SC 775.

1046(K) Moored starboard side to U.S.S. FULTON, in TANAPAG
        HARBOR, M.I.

12-16 MARCH, 1945.
        Conducted special tests. Fueled. Received orders to
        conduct coordinated wolf pack in area nine. Pack to
        consist of U.S.S. TINOSA (17.12.1), U.S.S. SPADEFISH
        (17.12.2), and U.S.S. TIRANTE (17.12.3) with Comtask
        Group 17.12, Commander R.C. LATHAM, USN., in TINOSA.

17 MARCH, 1945.
        All times hereafter are ITEM.

-2-

— page 82 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Ninth War Patrol.

(B) NARRATIVE (CONT'D)

17 MARCH, 1945.

1334 Underway from TANAPAG HARBOR, M.I., for ninth War Patrol.
1430 Joined escort SC 775, and proceeded in company with
     U.S.S. SPADEFISH, U.S.S. TIRANTE to follow later.
1950 Released escort. Conducting communication drills with
     U.S.S. SPADEFISH twice daily. Conducting individual ship
     and fire control drills daily.

18 MARCH, 1945.

1200 Position LAT. 15.32.8N., LONG. 141-21.8E.
1638 Submerged for trim and training.
1708 Surfaced.
1830 S/C #2. Exchanged recognition and calls with U.S.S.
     HADDOCK, by means of SJ radar.

19 MARCH, 1945.

0535 Submerged for trim dive.
0615 Surfaced.
1200 Position LAT. 18-05.5N., LONG. 137-32.7E.
1849 Slowed to one engine speed because of heavy head seas.

20 MARCH, 1945.

0417 Resumed two engine speed.
1200 Position LAT. 22-13.5N., LONG. 137-29.6E.

21 MARCH, 1945.

0310 S/C#3: SJ radar contact on something small, range 6800
     yards, bearing 330°T. We expected to meet U.S.S. BLUE-
     FISH, and SJ radar had interference in addition to that
     caused by U.S.S. SPADEFISH. This contact did not answer
     challenge on SJ and opened to the west as we avoided to
     the east.
0525 Submerged for trim dive.
0607 Surfaced.
0712 S/C#4. Sighted submarine on surface. Exchanged calls
     with U.S.S. DEVILFISH.
1120 A/C#4. Sighted unidentified plane, distance 10 miles.
1200 Position LAT. 26-48.2N., LONG. 137-31.9E.
1224 A/C #5. Sighted unidentified plane, looked like NICK,
     distance 8 miles. As we circled to left keeping stern
     toward, he continually presented angle on bow of 70°
     now, ducking behind clouds, but otherwise not offen-
     sive.
1234 Submerged with range 4 miles.
1251 Surfaced. All clear.

-3-

— page 83 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Ninth War Patrol.

(B) NARRATIVE (CONT'D)

22 MARCH, 1945.

1200 Position LAT. 29-15N., LONG. 133-37E.
1845 Sent message by SJ radar to U.S.S. SPADEFISH assigning
     patrol for 23 MARCH, 1945. Proceeding independently.

23 MARCH, 1945.

0605 Submerged at LAT. 28-47N., LONG. 129-26E., with APR 1
     signal on 153 mgs., increasing rapidly. Bow planes re-
     ported not rigged fully out by forward torpedo room.
     Found shear pin sheared in bow plane rigging gear. See
     major defects. Remained submerged at 150 feet to effect
     repairs. Force four sea made depth control at periscope
     depth impossible without bow planes.
1200 Position LAT. 28-47.8N., LONG. 129-02E.
1210 Shear pin in bow plane rigging renewed. Planes won't rig
     all the way out and so cannot tilt them. Running with
     bow planes rigged in. Will inspect on surfacing.
1216 Touched soft bottom lightly twice at 120 feet while com-
     ing to periscope depth. No damage.
1222 Took pictures of YOKOATE SHIMA and drew off to the south.
1613 Heard pinging dead ahead. Continued towards pinging. Fre-
     quently broached to 30 feet followed by flooding negative
     and catching her at 100 feet. Nothing in sight with ex-
     cellent view.
1645 Saw possible smoke in direction of pinging. All ahead
     standard.
1650 Sounded like an aerial bomb, loud compared to the depth
     charges, but not close. Depth control continues erratic.
1837 S/C #4. Finally sighted two PC type patrol vessels search-
     ing on northerly course. Shifted from normal approach
     course to normal evasion course, still at standard speed,
1909 Radar range on PC's 7800 yards.
1931 Surfaced in force five sea. Proceeding to night patrol
     line.
2130 Inspection of exposed bow plane gears in superstructure
     shows no trouble. Discovered planes lack ten degrees of
     being rigged in when indicator shows "in". Limit switches
     and indicator are out ten degrees. Realize we have not
     found cause, but planes operate properly with limit
     switches reset.
2230 Instructed SPADEFISH to proceed to area nine if no con-
     tact by 0200(I). Received her report of sinking one
     ship. No convoy course or speed given. Continuing search
     on best information available.

24 MARCH, 1945.

0604 Submerged for trim.

-4-

— page 92 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Ninth War Patrol
(F) SHIP CONTACTS

NO. | DATE | TIME | LAT | LONG | TYPE | INITIAL RANGE | Est. Course | Est. Speed | How contacted | REMARKS
----|------|------|-----|------||||||
1.  | 020951 | 20-44 | 162-52E | USS HADDOCK | 11,000 yds | 090 | 18 kts | Radar | U.S.S. SPADEFISH.
    |      |      | 16-24 |      | (SS231) SS |               |     |            | Sight |
    |      |      | 140-09 |      |                 |               |     |            | Interference |
2.  | 182040 | 16-24 | 140-09E | USS SPADE | 13,000yds | 300 | 12 knots | Radar | Challenge not answered
    |      |      | 16-24 |      | FISH SS |               |     |            |           | presumably USS BLUE-
    |      |      | 140-09 |      | (SS222) SS |               |     |            |           | FISH (SS222)
    | Exchanged calls
    | visually.
3.  | 191040 | 18-07N | 135-07E | USS BLUEFISH | 6,800yds | 090 | 12 knots | Radar | Doubtful contact,
    |      |      | 18-07 |      | SS (SS222) |               |     |            |           | lookout sighted but
    |      |      | 135-07 |      |                 |               |     |            |           | OOD did not see it
    | in scope by OOD.
4.  | 210310 | 24-33N | 137-34E | USS DEVILFISH | 16,900yds | 180 | 8 knots | Sight |
    |      |      | 24-33 |      | SS (SS292) |               |     |            |           |
    |      |      | 137-34 |      |                 |               |     |            |           |
5.  | 210712 | 25-44N | 137-27E | 2 PC Patrol | 10,900yds | 000 | 8 knots | Radar |
    |      |      | 25-44 | 137-27 |      |                 |               |     |            |           |
6.  | 231837 | 28-37N | 128-57E | 2 PC Patrol | 15,000yds | Unknown | Unknown | Sight |
    |      |      | 28-37 | 128-57 |      |                 |               |     |            |           |
7.  | 240702 | 28-57N | 127-41E | Unidentified | 18,000yds | 275 | 14 knots | Periscope | Pinged approx 25 live Japs
    |      |      | 28-57 |      | (Mast) |               |     |            |           | in boat.
    |      |      | 127-41 |      |                 |               |     |            |           | Turned toward. Sighted,
    | Pinged by.
8.  | 281240 | 29-14N | 124-52E | Sampan | 12,000yds | 000 | 8 knots | Radar | None.
    |      |      | 29-14 | 124-52 |      |                 |               |     |            |           |
9.  | 311710 | 31-26N | 129-17E | Small Landing | 6 mile | 225 | 2 knots | Periscope | Unable to establish
    |      |      | 31-26 |      | craft |               |     |            |           | communications.
    |      |      | 129-17 |      |                 |               |     |            |           | Exchanged calls and
    | changed recognition
    | signals and calls.
10. | 011224 | 30-30N | 129-06E | 6 mine craft | 14,000yds | 000 | 12 knots | Sonar | Unable to establish
    |      |      | 30-30 |      |                 |               |     |            |           | communication.
    |      |      | 129-06 |      |                 |               |     |            |           |
11. | 041240 | 29-20N | 137-20E | USS SENNETE | 12,000yds | 000 | 12 knots | Sonar |
    |      |      | 29-20 |      | (SS281) SS |               |     |            |           |
    |      |      | 137-20 |      |                 |               |     |            |           |
12. | 051602 | 22-06N | 137-23E | USS TRUTTA | 12,000yds | 000 | 12 knots | Periscope |
    |      |      | 22-06 |      | (SS408) |               |     |            |           |
    |      |      | 137-23 |      |                 |               |     |            |           |
13. | 05     | 21-24N | 141-51E | USS BONEFISH | 12,000yds | 000 | 15 knots | Radar |
    |      |      | 21-24 |      | (SS223) SS |               |     |            |           |
    |      |      | 141-51 |      |                 |               |     |            |           |
14. | 070215 | 15-17N | 141-51E | USS BONEFISH | 20 miles | 000 | 15 knots | Radar |
    |      |      | 15-17 |      | (SS223) SS |               |     |            |           |
    |      |      | 141-51 |      |                 |               |     |            |           |
15. | 070655 | 15-17N | 141-51E | Friendly | 5 miles | 000 | 14 knots | Periscope |
    |      |      | 15-17 | 141-51 |      |                 |               |     |            |           |

-12-

— page 94 —
CONFIDENTIAL

U.S.S. TINOSA (SS283) - Report of Ninth War Patrol.
I (K) MAJOR DEFECTS AND DAMAGE. - HULL & ENGINEERING.

Bow plane rigging - Bevel gear, pc E, and bevel pinion, pc
A2, Portsmouth Dwg.732-201, Bureau Dwg.312219M, became bad-
ly worn with the faces of several teeth gone. With the gears
in this condition the planes could not be rigged in and out.

Ship's force smoothed these gears as much
as possible and reinstalled, attaining a condition where the
planes could be rigged in and out by hand at slow speeds sub-
merged.

The direct cause of this casualty is be-
lieved to be in the accomplishment of approved SHIPALT SS/
S22(815) of 20 December, 1944 (Modification of bow plane
rigging gear to permit rigging in planes on 15° dive angle).

The alteration as performed on U.S.S.
TINOSA did not allow the bow planes to rig in far enough
so the bull gears were past their dead center as designed.
Consequently the weight of the bow planes, plus the driving
force of heavy seas, tending to rig out the planes, was re-
sisted by the entire gear train rather than the heavy bull
gears. Under continual pounding and stress, the weakest por-
tion of this gear train gave way. A contributory cause was
undoubtedly the stress created by the "bite" of the planes
before reaching a fully rigged out position when making a
dive at high speed.

When this alteration is accomplished,
the superstructure should be indented sufficiently to allow
the bow planes to rig in far enough so the bull gears pass
their dead center.

Correction of this defect will include
renewal of bevel gear and bevel pinion as well as restoring
bow planes to their zero tilt position for rigging.

Bow buoyancy vent - Bow buoyancy vent would not close under
hydraulic power when the boat was below periscope depth. This
failure is a repeater from the 8th patrol, Pearl Harbor in-
vestigated the operation of the entire system and realigned
the vent operating gear, but apparently without effect. Cause
of failure is still unknown.

Periscopes - No.1 periscope, (MK 4, ST type) leaked
excessively around the packing gland. The FULTON at SAIPAN,
attempted to remedy this by replacing the one ring of garlock
packing, installed by Pearl Harbor, with three rings of flax
packing.

-14-

— page 95 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Ninth War Patrol.
(K) MAJOR DEFECTS AND DAMAGE (Cont'd).
    packing. On arrival in area it was necessary to install an
    additional ring of flax packing and set up fully on the
    gland to stop leakage. This resulted in making it almost
    impossible to rotate the periscope. Not enough flax packing
    was available on board to completely repack this periscope.

    Ordnance and Gunnery - No Comments.

(L) RADIO
    Radio traffic was heavy during this patrol. In general,
    reception was good; and our many transmissions were cleared
    without difficulty.

    Continuous application of heat to the antenna trunk was
    necessary to keep the low ground readings on all antenna
    leads from dropping to zero. This difficulty was experienced
    last patrol also, and measures taken during last refit were
    inadequate if not wholly ineffectual.

    Two RBS receivers were carried on this patrol. Their per-
    formance was good, except when heavy Japanese interference
    was encountered. In such cases the finer tuning qualities of
    the RAL receiver made possible a clearer signal using the
    RAL. The RBH receiver was carried in the wardroom for the
    first time this patrol, and was much appreciated by all
    officers.

    Installation of a TCK transmitter in submarines to replace
    the TBL is recommended to cut down tuning time prior to trans-
    mitting and to increase CW power.

    The SD antenna was used with notable success on 28 March,
    1945 at 1230(I) in clearing a message to NPM at a distance of
    4000 miles. A frequency of 16940 Kcs was used, with a strength
    5 signal and no interference.

    It should be made a matter of routine for NPN and NPM
    operators always to authenticate their "go ahead" operating
    signal in extra transmission by the submarine, requesting
    authentication, is now required in order to avoid clearing
    your message with a Japanese station.

    The WOPLCO circuit was found to be jammed with extraneous
    transmissions, Q-signals, and enemy transmissions. Circuit
    discipline was lacking. With the ever-increasing load being
    placed on this circuit, positive steps should be taken to

-15-

— page 98 —
CONFIDENTIAL
(M) RADAR(CONT'D)

The APR 1 scope is calibrated on the basis of ten for
saturation. The operator keeps his gain at ten until sat-
uration is reached. He then decreases the gain to main-
tain saturation. The strength of the APR 1 signal is then
reported to the bridge simply as " 176 mgc at 4 points"
meaning four tenths of saturation with gain on ten, or "176
mgc at 10 point 8" meaning saturation with gain reduced
to eight. Based on this system SJ and SD both detected
aircraft as follows:

APR 1                               SJ             SD
176 mgc at 10:8                     8 miles        8 miles
176 mgc at 10.7                     3 miles        3 miles

While in the area this 176 mgc signal was thought to
be Jap aircraft radar. But later, while on lifeguard sta-
tion with B-29 air cover, 176 mgc was detected again,
pulse width 7-12 microseconds. This may have come from
friendly AEK units.

It is recommended that our research section develop ,
keep up to date, and publish for benefit of submarines go-
ing on patrol, a list by frequencies of various radar. This
list should contain U.S. Army, U.S. Navy and Japanese radar
as well as unexplained signals listed in submarine patrol
reports. Such a list is at present scattered throughout
several publications, letters, patrol reports, and patrol
instructions. This list to be valuable should be in order
of frequencies so an APR 1 signal can be immediately re-
ferred to one basic list.

-18-

— page 102 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Ninth War Patrol:
(N) SONAR GEAR AND SOUND CONDITIONS, (CONT'D)

     8. A defective tube, V802, was replaced from on board
        spares. This was in the indicator circuit in the conning
        tower.

     9. Also, in the indicator circuit, the resistor, R807,
        was found to have a value several times in excess of that
        given in the circuit diagram. This was replaced from on-
        board spares.

     10. It is recommended that the allowance of on-board
         spares be increased to provide a replacement for condenser,
         C815. Lacking practical experience, the allowance of spares
         should also be increased to provide replacement for any other
         parts the manufacturer can predict may break down.

     11. The K3 reversing relay should be replaced with one
         designed to be sturdy enough to perform the task expected
         of it.

-22-

— page 107 —
FF12-10(A)/L16-3(18)
Serial 0859
CONFIDENTIAL
THIRD ENDORSEMENT to
TINOSA Report of
Ninth War Patrol.

COMSUBSPAC PATROL REPORT NO. 722
U.S.S. TINOSA - NINTH WAR PATROL.

From:
To :
Via :
Subject:

1.
the East China Sea under the command of Commander R. C. Latham, U.S.
Navy. The commanding officer of the TINOSA was also in command of a
coordinated attack group including the U.S.S. SPADEFISH (SS411) and
the U.S.S. TIRANTE (SS420).

2. The TINOSA accomplished a special mission with great
skill and determination. This mission is being made the subject of a
separate report. The TINOSA captured two enemy aviators during this
patrol. No torpedo targets were encountered and the TINOSA was forced
to leave area early because of a bow plane casualty.

3. Award of Submarine Combat Insignia for this patrol is
authorized.

4. The Commander Submarine Force, Pacific Fleet, congra-
tulates the commanding officer, officers, and crew of the TINOSA for
the successful accomplishment of a very important special mission.

DISTRIBUTION:
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[HANDWRITTEN: 2nd Copy]
SUBMARINE FORCE, PACIFIC FLEET
Care of Fleet Post Office,
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18 April 1945.

NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.

The Commander Submarine Force, Pacific Fleet.
The Commander-in-Chief, United States Fleet.
The Commander-in-Chief, U. S. Pacific Fleet.

U.S.S. TINOSA (SS283) - Report of Ninth War Patrol
(1 March to 7 April 1945).

The ninth war patrol of the TINOSA was conducted in

[HANDWRITTEN: nr]

[STAMP: MERRILL COMSTOCK, JR. FILES]
[STAMP: Room 2055]
[STAMP: FILE TO 26 APR 1945 / L16-3(18) / 168337]
[STAMP: APR 27 1945]
[STAMP: RECEIVED NAVY DEPARTMENT]
ComsubspacSubordcom (3)
All Squadron and Div.
Commanders, Pacific (2)
Substrainpac (2)
All Submarines, Pacific (1)
[SIGNATURE: R. Hynes 2nd]
E. L. HYNES, 2nd,
Flag Secretary.

— page 108 —
FC5-20/A16-3
Serial: 074
CONFIDENTIAL

SECOND ENDORSEMENT TO
CO TINOSA Report of 9th
War Patrol dated 7 April
1945 (Serial: 011)

From:
To :
Via :

Subject:

1.
Submarine Division TWO HUNDRED TWO.

2.
Commanding Officer, officers and men of the TINOSA and wishes them
successful hunting unmarred by materiel difficulties on their next
patrol.

SUBMARINE SQUADRON TWENTY

Care of Fleet Post Office,
San Francisco, California,
9 April 1945.

The Commander Submarine Squadron TWENTY.
The Commander-in-Chief, United States Fleet.
(1) The Commander Submarine Force, Pacific Fleet.
(2) The Commander-in-Chief, United States Pacific
Fleet.

U.S.S. TINOSA (SS283) - Report of NINTH War Patrol.

Forwarded, concurring in the remarks of Commander

The Commander Submarine Squadron TWENTY welcomes the

[SIGNATURE: L. S. Parks]
L. S. PARKS.

— page 109 —
SUBMARINE DIVISION TWO HUNDRED TWO

Care of Fleet Post Office
San Francisco, California
8 April 1945

FB5-202/A16-3

Serial: 012

CONFIDENTIAL

FIRST ENDORSEMENT
CO USS TINOSA ltr. SS283/A16-3
Ser: 011 of 7 april 1945
Report of 9th War Patrol

From: Commander Submarine Division TWO HUNDRED TWO.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarine Squadron TWENTY.
(2) The Commander Submarine Force, Pacific Fleet.
(3) The Commander-in-Chief, United States Pacific
Fleet.

Subject: U.S.S. TINOSA (SS283) - Report of War Patrol
number NINE.

1. The ninth war patrol of the TINOSA conducted in
the EAST CHINA SEA was of thirty-eight days duration, six of
which were spent in the assigned area. The patrol was terminated
early due to bow plane casualty. The Commanding Officer of the
TINOSA was in command of a coordinated attack group including
the SPADEFISH and TIRANTE.

2. The TINOSA made but three contacts with enemy sur-
face craft, none of which were worthy of torpedo attacks. Enemy
air activity was light.

3. The TINOSA completed one special mission which is
the subject of a separate report.

4. It was unfortunate that a bow plane casualty
caused an early termination of the patrol. Every effort was made
to effect repairs at sea.

5. The TINOSA returned from patrol clean and in very
good material condition. SUBMARINE SQUADRON TWENTY should have
no difficulty in making her ready for sea in the allotted ten day
repair period.

4. The Commanding Officer, Officers and Crew are
congratulated on their return from this short but difficult
patrol.

[SIGNATURE: Rob Roy McGregor]
ROB ROY MCGREGOR.

— page 110 —
hf

U.S.S. TINOSA (SS283)

Care of Fleet Post Office,
San Francisco, California,
16 May, 1945.
DECLASSIFIED-ART. 0445, OPNAVINST 5510.C
[HANDWRITTEN: By] [SIGNATURE: S.O. Gold] [HANDWRITTEN: DATE 6/26/72]

SS283/A16
Serial: (015)
CONFIDENTIAL
[STAMP: DECLASSIFIED]
From: The Commanding Officer:
To : The Commander in Chief, UNITED STATES FLEET.
Via : (Official Channels).

Subject: U.S.S. TINOSA (SS283), Report of War Patrol
number TEN.

Enclosures: (A) Subject report.
(B) Track Chart (Comsubspac only).

1. Enclosure (A), covering the TENTH War Patrol of
this vessel conducted in the TRUK ISLANDS area during the
period 28 April, 1945 to 16 May, 1945, is forwarded herewith.

[SIGNATURE: R.C. Latham]
R.C. LATHAM.

[HANDWRITTEN: FILMED]
[HANDWRITTEN: 126681]

— page 111 —
U.S.S. TINOSA (SS283) - Report of TENTH War Patrol

(A) PROLOGUE

Arrived GUAM from NINTH WAR PATROL on 7 April, 1945.
Completed short refit by Submarine Division TWO HUNDRED
TWO, and U.S.S. PROTEUS on 18 April, 1945. Major work
accomplished was the overhaul of bow plane rigging in-
cluding manufacture and installation of new bevel gear
and bevel pinion in superstructure, replacement of da-
maged superstructure plating forward, and overhaul of
FM Sonar. Of note is that replacement of the FM pro-
jector improved performance about 800 %. TINOSA is
deeply appreciative of the comforts and rest extended by
Camp Dealey and the full cooperation of and excellent
refit accomplished by Submarine Division 202, the U.S.S.
PROTEUS, and Comsubspac's FM Sonar Staff.

Conducted tests and training 21-23 April, 1945, firing
four exercise torpedoes. Conducted special tests on 24-
26 April, 1945. Ready for sea 28 April, 1945.

— page 112 —
U.S.S. TINOSA (SS283) - Report of TENTH War Patrol

(B) NARRATIVE.

     The Executive Officer, Lieutenant-Commander, R.W. PAINE,
Jr., U.S. Navy, was detached and Lieutenant-Commander
H.J. SMITH, Jr., U.S. Navy, assumed duties as Executive
Officer and Navigator. Lieutenant F.C. BROOKS, (D)(L),
U.S.N.R., reported aboard for duty. Lieutenant-Commander
R.B. LAKIN, Royal Navy, reported aboard as observer.

OFFICERS attached to U.S.S. TINOSA, and total number of patrols
including present patrol:

                                                      PATROLS
LATHAM, Richard G.           Commander, USN.             4
SMITH, Harvey, J. Jr.        Lt-Comdr., USN              0
SANDERS, C.R.                Lieut (DE) USNR             4
BROOKS, Frank C.             Lieut.(D)(L), USNR          3
WEAVER, Bruce S.             Lieut(jg).(E).USNR          7
GROSE, Herschel O.           Lieut(jg).(E)R-L, USNR      6
SALISBURY, Guy F.            Lieut(jg).(E).USNR          4
SIEGFRIED, Clyde W.          Lieut(jg)., USN             6
OLSEN, John (n)              Ensign(DE) USNR             5
CLUTTERHAM, David R.         Ensign(D).USNR              3

Chief Petty Officers, and number of patrols including present
patrol:

WELCH, Freeman (n)           CTM(T), USN (SS)            4
WILSON, Norval D.            CMOMM(PS)(SS)USNR           5
STOKES, Victor L.            CIM(PA)(GY)(IC)
                             (SS), USN                   5
BAIRD, Floyd C.              CMOMM(T)(SS), USNR          3

-1-

— page 113 —
(B) NARRATIVE (CONT'D)

All times are KING(-10)

28 APRIL, 1945
1543 Underway from APRA HARBOR, GUAM, for tenth war patrol.
U.S.S. BARON escort.
1654 Submerged.
1738 Surfaced.

29 APRIL, 1945
0310 S/C#1. SJ radar contact at 17,000 yards. Escort ex-
changed recognition.
0940 Released escort.
1200 Position. Lat.09-38N., Long 147-41E.
1721 Entered Area.

30 APRIL, 1945.
This night was enlivened by SJ radar pips on birds,
some of whom we chased and some of whom chased us.
0400- The Japs seem to have an air patrol out using 147
0520 mcs radar. APR-1 had 147 mc signals to saturation
with gain reduced to 7. No contact on SJ, SD, or
sight.

0520 Submerged on life-guard station.
1133 A/C#1. Sighted 12 liberators and 2 superforts over
TRUK.
1135 Surfaced and established communications.
1200 Position. Lat. 07-50N., Long. 151-38E.
1207 A/C #2. Submerged as 4 planes came in low and fast
on a collision course from North. These were not
part of the original groups. No IFF. Planes sheered
off, as we went under, and were then identified as
Liberators.
1216 Surfaced.
1220 Watched 16 liberators and 2 forts assemble and head
for GUAM.
1230 A/C#3. Watched Jap plane leave MOEN ISLAND, and head
for us flying very low.
1231 Submerged.
1430 A/C#4. Watched plane patrolling on East-West courses
apparently looking for us. This fellow was positively
identified as a MARTIN MARINER, but was not expected.
Tried to contact him on radio by exposing SD antennae
with no success.
1504 Surfaced with range to A/C#4 about 8 miles. Still
no radio contact. He flew off towards GUAM and dis-
appeared.
1605 A/C#5. Watched unidentified plane cross about ten
miles astern on southerly course headed for TRUK.

-2- ENCLOSURE "B"

— page 117 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of TENTH War Patrol
(B) NARRATIVE

8 MAY, 1945 (CONT'D)

1903 Surfaced. Started for SOUTH PASS.

9 MAY, 1945

Returning to lifeguard station.
0506 Submerged.
1117 Surfaced.
1124 A/C#21: One or more liberators in sight until 1220. Un-
     able to get planes to talk to us although we could hear
     planes. They did not call us.
1200 Position Lat. 07-55N., Long 151-36E.
1220 Submerged when unidentified plane left TRUK ISLANDS fly-
     ing very low and directly at us. This was probably a
     Liberator, but was unable to identify and his tactics
     were not friendly.
1230 Nothing in sight through periscope.
1905 Surfaced.
2200 Test fired 20MM and 40MM guns. Intend to reconnoiter
     NOMWIN ISLAND. There is a reported seaplane base there.
     "JAKE" must go somewhere. If he lands at NOMWIN perhaps
     we can catch him on the water.

10 MAY, 1945

0505 Submerged just south of NOMWIN ISLAND.
1200 Position Lat. 8-25N., Long.151-49E.
1556 A/C #22. Sighted PBY circling low over NOMWIN ISLAND.
1622 PBY departed to south.
1718 PBY back again. Took pictures of NOMWIN ISLAND and PBY.
     Island bears 270°(T), range 3200 yards. Attempted to con-
     tact PBY on radio, through SD antennae, with no success.
     NOMWIN ISLAND appears deserted.
1912 Surfaced.

11 MAY, 1945.

Enroute SOUTH PASS.
0520 Submerged off SOUTH PASS.
1200 Position Lat. 7-09N., Long .151-43E.
1559 Took pictures of gun emplacement on PULU ISLAND, bearing
     328°(T), range 3800 yards.
1903 Surfaced. Much unreadable visual signalling on main islands.

12 MAY, 1945.

Intend to patrol NORTHEAST PASS unless lifeguard duties
interfere.
-6- ENCLOSURE (A)

— page 121 —
CONFIDENTIAL

U.S.S. TINOSA (SS283) - Report of TENTH War Patrol

(H) ATTACK DATA (CONT'D)

U.S.S. TINOSA                 GGun Attack #1                               Patrol #10.
Bombardment of ULUL ISLAND.
Time 2129 Date: 5/14/45. Lat.8-34.6N., Long 140-39.5E.

Target Data - Damage Inflicted.

Sunk: None.
Damaged:Japanese Installations on ULUL ISLAND.
Damage determined by: Saw large column of smoke.

Details of Action

Restrictions imposed by despatch orders on leaving area
forced bombardment to be made at night after moonset.
A scale reproduction of ULUL ISLAND and reefs to the west-
ward was made and fixed on the DRT in the conning tower. Fox
Mike Sonar presented a perfect PPI picture of the reefs. The
fathometer was manned continuously. These three considerations
provided perfect navigation 400 feet off the 10 fathom curve,
and about 500 yards from the beach; provided an accurate plot
of our maneuvers; gave excellent range and deflection to the gun
on a nearly invisible target; and left SJ radar free for spotting
and sweeping. The quality of the fire control and navigation
achieved by this system was very gratifying.
Opening range was 1750 yards, closest range 1100 yards.
The only indication of damage inflicted was a column of
black smoke from the target. Details could not be discerned.
There was no return fire.
A special watch for signs of radar or radio activity from
the target was maintained. No signals were detected.
A false SD contact caused haste in securing topside with the
result that two 5" ready ammunition lockers on deck subsequently
flooded. Six rounds of 5" were jettisoned after being flooded.

Ammunition Expended.

30 rounds 5" -- On target.
60 " 40MM-- " ""
20 " 20MM-- " ""
400 " 50cal -- " ""
6 " 5" -- Jettisoned.

(I) MINES

No mines were encountered.

-10- ENCLOSURE (A)

— page 126 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of TENTH War Patrol.
(Q) PERSONNEL
    OFFICERS: The performance of duty of each officer left nothing
              to be desired.

    ENLISTED PERSONNEL: The morale, state of training and per-
                        formance of duty by the crew is exceptional,
                        fine throughout.

    Number of men on board during Patrol                               79
    Number of men qualified at start of Patrol                         51
    Number of men qualified at end of Patrol                           58
    Number of unqualified men making first Patrol                      11
    Number of men advanced in rating during Patrol                      6
    Number of men transferred after last Patrol                         8

        School of the boat was held daily by all officers. The
    enthusiasm for qualification shown by new members of the crew
    is very gratifying. Unfortunately the duration of this patrol
    did not permit qualification of more members of the crew. It
    was not deemed advisable to shorten the educational program
    to fit the length of the patrol.

(R) MILES STEAMED                                          FUEL USED
    GUAM to AREA           371                             7450 gallons.
    In AREA               2489                            24469 gallons.
    AREA to GUAM           371                             5168 gallons.
    TOTAL                 3231            TOTAL           37,087 gallons.

(S) DURATION
    Days GUAM to AREA        2
    Days in AREA            15
    Days AREA to GUAM        2

(T) FACTORS OF ENDURANCE REMAINING
    TORPEDOES           - 21 Mk XVIII, 5 Mk XXVII
    FUEL                - 79,707 gallons.
    PROVISIONS          - 60 Days.
    PERSONNEL           - Indeterminate.

    Limiting factor of this patrol - terminated by despatch orders.

                                -15-                       ENCLOSURE (L)

— page 127 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of TENTH War Patrol.
(U) COMMUNICATIONS, RADAR, AND SONAR COUNTERMEASURES.

— page 128 —
SUBMARINE DIVISION TWO HUNDRED TWO

Care of Fleet Post Office,
San Francisco, California.

27 May 1945.

FB5-202/A16-3
Serial: 027

CONFIDENTIAL

FIRST ENDORSEMENT to
CO USS TINOSA ltr. SS283/A16
Ser: 015 of 16 May 1945.
Report of 10th War Patrol.

From: Commander Submarine Division TWO HUNDRED TWO.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarine Squadron TWENTY.
(2) The Commander Submarine Force, Pacific Fleet.
(3) The Commander-in-Chief, United States Pacific Fleet.

Subject: U.S.S. TINOSA, (SS283) - Report of War Patrol Number TEN.

1. The tenth war patrol of the TINOSA, conducted in the Truk
Island Area was of nineteen days duration, fifteen of which were spent in the
assigned area.

2. Despite thorough area coverage no contacts were made with
enemy surface craft. Enemy air activity was negligible.

3. On the afternoon of 3 May the TINOSA while on the surface
was closely bombed by an enemy plane. Fortunately no damage was sustained.

4. On 14 May the TINOSA made a gun attack with all calibers
against Japanese installations on Ulul Island. Operation orders confined
the bombardment to be made at night after moonset. The attack was excellently
planned and conducted against a nearly invisible target. A column of black
smoke was the only indication of damage inflicted.

5. The TINOSA was available for lifeguard services but was
afforded no rescue opportunities.

6. A Submarine Squadron Twenty photographer assigned to the
TINOSA took numerous reconnaissance pictures.

7. The TINOSA returned from patrol clean and in very good mate-
rial condition. Squadron Twenty facilities will be strained to the utmost
however to effect necessary repairs in the five day period allotted.

8. The Commanding Officer, officers and crew are congratulated
on their return from this short patrol in which, unfortunately, no opportunity
was afforded to engage the enemy.

[SIGNATURE: Rob Roy McGregor]
ROB ROY MC GREGOR.

— page 129 —
SUBMARINE SQUADRON TWENTY
Care of Fleet Post Office,
San Francisco, California.
29 May 1945.

FC5-20/A16-3

Serial: 0120

CONFIDENTIAL

SECOND ENDORSEMENT to
CO TINOSA Report of 10th
War Patrol (Serial 015)
of 16 May 1945.

From: The Commander Submarine Squadron TWENTY.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarine Force, Pacific Fleet.
(2) The Commander-in-Chief, United States Pacific
Fleet.

Subject: U.S.S. TINOSA (SS283) - Report of War Patrol number
TEN.

1. Forwarded, concurring in the remarks of Commander
Submarine Division TWO HUNDRED TWO.

2. The Commander Submarine Squadron TWENTY congratulates
the Commanding Officer, officers and men of the U.S.S. TINOSA on
the completion of their ship's tenth patrol, and hopes that her
eleventh will present them with the opportunity for another of the
productive and aggressive patrols characteristic of the TINOSA.
It is noted that the U.S.S. TINOSA enjoys the splendid record of
nine consecutive successful war patrols.

[SIGNATURE: u. S. (faint, illegible)]
L. S. PARKS.

— page 130 —
FF12-10(A)/Ar6-3(18)
Serial 01435 [HANDWRITTEN: 3rd Copy]
[STAMP: CONFIDENTIAL]
THIRD ENDORSEMENT to
TIMOSA Report of
Tenth War Patrol

SUBMARINE FORCE, PACIFIC FLEET
Care of Fleet Post Office,
San Francisco, California,
13 June 1945
NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.
Ga

[STAMP: RECEIVED S-C FILES]
[HANDWRITTEN: 23c Room 2055]
[STAMP: DATE 10 23 JUN 1945]
[STAMP: File No. (A) Ar6-3/23/SS]
[STAMP: Doc. No. 175136]
[STAMP: Copy No. 4]

COMSUBSPAC PATROL REPORT NO. 778
U.S.S. TIMOSA - TENTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet
To : The Commander in Chief, United States Fleet.
Via : The Commander in Chief, U. S. Pacific Fleet.

Subject: U.S.S. TIMOSA (SS283) - Report of Tenth War Patrol
(28 April to 16 May 1945).

1. The tenth war patrol of the TIMOSA, under the command of Commander
R. C. Latham, U. S. Navy, was conducted in the vicinity of Truk. In addition to
offensive patrol the TIMOSA was available for lifeguard services.

2. The absence of surface ships and the meagerness of enemy aircraft
patrols are indicative of the effectiveness of the blockade now imposed against this
once important major Japanese base. The use of FM sonar to determine the contour of
the reef and thus accurately fix the ship's position for the evening shore bombard-
ment is noted with interest.

3. Award of Submarine Combat Insignia for this patrol is not authorized.

4. The Commander Submarine Force, Pacific Fleet, congratulates the
commanding officer, crew, and officers of the TIMOSA on the completion of this
patrol, and wishes them better luck in the matter of targets on their next patrol.
W. S. LANGLEY.

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CNO (5)
Cincpac (6)
JICPOA (1)
AdJICPOA (1)
Conservpac (1)
Cinclant (1)
Comsubslant (8)
S/M School, NL (2)
CO, S/M Base, PH (1)
Comsopac (2)
Comsowespac (1)
Comsubs7thFlt (Fwd Echelon) (2)
Comsubs7thFlt (Rear Echelon) (2)
Comnorpac (1)
Comsubspac (3)
[STAMP: CONFIDENTIAL]

[STAMP: OFFICE OF THE CHIEF OF NAVAL OPERATIONS]
[STAMP: FILED UNDER]
[STAMP: JUN 25 1945]
[STAMP: Comsubspac Cor]
[STAMP: SUBM, M1]
[STAMP: In Chief, U. S. Pacific Fleet]
All Squadron and Division (20)
Commanders, Pacific (2)
Substrainpac (3)
All Submarines, Pacific (2)
(1)
[SIGNATURE: W. S. Langley]
W. S. LANGLEY,
Asst. Flag Secretary.

— page 131 —
hf [HANDWRITTEN: scribbled marks]
SS283/A16
Serial: (016)
[CROSSED OUT: DECLASSIFIED]
From:
To :
Via :
U.S.S. TINOSA (SS283)
Care of Fleet Post Office,
San Francisco, California,
4 JULY, 1945.

The Commanding Officer:
The Commander in Chief, UNITED STATES FLEET.
Official Channels.

Subject: U.S.S. TINOSA (SS283) - Report of War Patrol
number ELEVEN.

Enclosures: (A) Subject Report.
(B) Track Chart (ComSubPac only).

1. Enclosure (A), covering the ELEVENTH War Patrol
of this vessel conducted in the Japan Sea during the period
29 May, 1945 to 4 July, 1945, is forwarded herewith.

DECLASSIFIED-ART. 0445, OPNAVINST 5510.1C
BY [SIGNATURE: J.G.M.] DATE [HANDWRITTEN: 6/20/78]
[SIGNATURE: R.C. Latham]
R.C. LATHAM.

[HANDWRITTEN: FILMED]
[HANDWRITTEN: 133255]

— page 145 —
This looks like a page from a U.S. Navy submarine patrol report during World War II, specifically for the USS TINOSA (SS283) for its Eleventh War Patrol. It details daily events, including contacts with enemy vessels, torpedo attacks, and other observations.

Here's the transcription:

CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol

— page 147 —
CONFIDENTIAL: U.S.S. TINOSA(SS283) - Report of ELEVENTH War Patrol.

(B) NARRATIVE
30 JUNE, 1945.
0414(L) Submerged for trim.
0428(L) Surfaced.
1200(L) Position. Lat.29-17N., Long.177-32E.

30 JUNE, 1945
Crossed 180th meridian, repeated this date.
0130(Y) Sighted U.S. Submarine probably U.S.S. ASPRO. Our SJ radar
          temporarily out of commission and no sign als exchanged.
0350(Y) Sighted U.S. ATR26. Avoided.
0503(Y) Contacted plane escort.
0719(Y) Picked up MIDWAY pilot.
0738(Y) Commenced sound tests in lagoon.
0823(Y) Completed sound tests.
0834(Y) Moored MIDWAY ISLAND. Received 28,948 gallons fuel.
1334(Y) Underway for PEARL.
1515(Y) Submerged for trim.
1520(Y) Surfaced.
1600(Y) Plane escort departed.

1 JULY, 1945.
0010(Y) First of four friendly ship contacts. Avoided.
1200(Y) Position. Lat. 24-11N., Long.173-48W.

2 JULY, 1945.
0540(X) Submerged for trim.
0602(X) Surfaced.
1200(X) Position. Lat. 22-23N., Long.168-25W.

3 JULY, 1945.
0500(X) Submerged for trim.
0516(X) Surfaced.
0536(X) Sighted and exchanged calls with U.S.S. SKATE by blinker.
1200(W) Position. Lat. 20-47N., Long.163-18W.
1330(W) Sighted and exchanged calls and chatter with U.S.S. POGY.
1703(W) Commenced sighting and forming up for rendezvous with USS
          SPIDEFISH, FLYING FISH, SKATE, and BOFIN.

4 JULY, 1945
0600(W) Rendezvoused with escorts U.S.S. PRUITT and PC782.
0800(W) Submerged on signal.
0806(W) Surfaced on signal.
1120(W) Moored to pier Sail Nine, U.S. Submarine Base, Pearl
          Harbor T.H.

-16-

— page 149 —
(F)
IP CONTACTS

| NO. | DATE | TIME | LAT. | LONG. | TYPES(s) | INITIAL RANGE | EST. COURSE | EST. SPEED | HOW CONTACTED | REMARKS |
|---|
| 1. | June 4 | 1715 (I) | 27-18N | 139-24E | DD | 28,000 yds | C-180 | S-Unk. | Day | U.S.S. BOWFIN |
| | | | | | | | C-270 | S-Unk. | Surf. | Friendly Destroyer. |
| 2. | June 4 | 1327 (I) | 30-31N | 129-33E | SS | 16,000 | C-180 | S-15 | Night | U.S.S. SCABBARD FISH |
| | | | | | | | C-060 | S-15 | Radar | Received challenge. Aban- | doned attack because of | Op. Orders. |
| 3. | June 4 | 2215 (I) | 31-54N | 128-59E | SS | 12,000 | C-060 | S-12 | Night | U.S.S. SCABBARD FISH |
| | | | | | | | C-090 | S-12 | Radar | Unidentified. Time | doned attack because of | Op. Orders. |
| 4. | June 4 | 2350 (I) | 32-00N | 128-56E | UNK | 31,000 | C-090 | S-Unk. | Night | Avoided. |
| 5. | June 6 | 2118 (I) | | | UNK | 6,000 | C-090 | S-Unk. | Night | Avoided. |
| | | | | | | | C-100 | S-Unk. | Radar | |
| 6. | June 6 | 2358 (I) | | | UNK | 12,700 | C-100 | S-8 | Night | Avoided. |
| | | | | | | | C-100 | S-8 | Radar | |
| 7. | June 7 | 0138 (I) | | | UNK | 4,750 | C-335 | S-8 | Day | Believed to be friendly Sub. |
| | | | | | | | C-335 | S-8 | Per. | |
| 8. | June 7 | 2034 (I) | 37-28N | 129-59E | UNK | 4,000 | C-035 | S-6½ | Day | Attacked and sank. |
| | | | | | | | C-035 | S-6½ | Per. | Attacked. One circular run. Believed dama- | ged. Could not find target | after surfacing. |
| 9. | June 8 | 1422 (I) | 37-31N | 129-11E | SCL | 8,100 | C-285 | S-8 | Day | Attacked and sank. |
| | | | | | | | C-285 | S-8 | Radar | Fishing Trawler. |
| 10. | June 9 | 1524 (I) | 38-28N | 130-31N | AK | 62,000 | C-005 | S-10 | Day | Attacked and sank. |
| | | | | | | | C-005 | S-10 | Per. | Probably light | loaded AK. |
| 11. | June 10 | 0920 (I) | 37-35N | 129-19E | Trawler | 9,000 | C-310 | S-6 | Day | Avoided. Probably PC. |
| | | | | | | | C-310 | S-6 | Per. | Could not reach firing | position. |
| 12. | June 12 | 1055 (I) | 37-34N | 129-17E | Truck | 10,000 | C-110 | S-7 | Night | Avoided. Probably PC. |
| | | | | | | | C-110 | S-7 | Radar | Received challenge. No Ra- | dar contact. Avoided. |
| 13. | June 12 | 1200 (I) | 37-34N | 129-17E | Patrol | 5,000 | C-320 | S-7 | Night | U.S.S. FLYING FISH |
| | | | | | | | C-320 | S-7 | Surf. | Probably light | loaded AK. |
| 14. | June 13 | 0238 (I) | 37-33N | 129-22E | UNK | 5,300 | C-020 | S-7 | Night | Avoided. |
| | | | | | | | C-020 | S-7 | Radar | |
| 15. | June 14 | 2103 (I) | 37-33N | 129-22E | UNK | 7,800 | C-030 | S-6.5 | Night | Avoided. |
| | | | | | | | C-030 | S-6.5 | Radar | |
| 16. | June 16 | 2126 (I) | 37-29N | 129-20E | UNK | 9,500 | C-045 | S-6.5 | Night | Avoided. |
| | | | | | | | C-045 | S-6.5 | Radar | |
| 17. | June 18 | 0404 (I) | 37-28N | 128-56E | UNK | 9,500 | C-045 | S-6.5 | Night | Avoided. |
| | | | | | | | C-045 | S-6.5 | Radar | |

-18-
ENCLOSURE (A)

— page 150 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol
(FISHER CONFIDENTIAL (CONT'D)

| NO. | TIME | DATE | LAT | LON | TYPES(s) | INITIAL | RANGE | BEARING | COURSE | SPEED | HOW CONTACTED | REMARKS |
|---|
| 18. | 2312(I) | June 19 | 35-20N | 130-00E | 3 | Patrol | 6,700 yds | 0-140 | Day | 3000 | Avoided | Properly Lighted | Radar | |
| 19. | 0305(I) | June 19 | 35-48N | 130-23E | AK | Med. | 11,500 yds | 0-100 | Day | 7.5 | Attacked and sank. |
| | 1729(I) | June 20 | 36-12N | 130-58E | AK | | | | | | | |
| 20. | 2244(I) | June 22 | 43-44N | 136-44E | AQ | Large | 25,000 yds | 0-200 | Night | | Attacked and sank. | Radar | |
| 21. | 2255(I) | June 24 | 45-47N | 137-17E | Large | | 25,000 yds | 0-290 | Night | | Avoided | Russian | Surf. | |
| 22. | 0100(I) | June 25 | 46-00N | 137-20E | Patrol | | 6,800 | 0-270 | Night | | Avoided | Russian | Radar | |
| 23. | 2344 | June 25 | 46-02N | 137-23E | SS | | 6,500 | 0-210 | Night | | U.S.S. DACE. | Radar | |
| 24. | | June 25 |

NOTE: In addition to the above contacts many small fishing
craft were contacted along the KOREAN coast with an
extremely strong concentration of these craft in the
vicinity of BOKUKO KO.

-19-
ENCLOSURE (A)

— page 152 —
CONFThe following text is a transcription of the provided image:

CONFIDENTIAL U.S.S. TINOSA(SS283) - Report of ELEVENTH War
                                                              Patrol.

— page 155 —
CONFIDENTIAL: U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol,

(H) ATTACK DATA (CONT'D)
TORPEDO ATTACK NO 2. Date: 6-10-45.

Tube Fired:           7           8           9           10
Zone Time:            2042-47(I)  2043-00(I)  2043-10(I)  2044-27(I)
Range:                1700        1700        1700        2500
Torpedo Run:          1500        1500        1500        2400
Target Bearing:       040°(T)     040°(T)     040°        0280(T).
Track Angle:          74° P       78° P       78.5° P     93° P
Gyro Angle:           151         147         147.5       132
Depth Set:            6           6           6           6
Power:                High        High        High        High
Hit or Miss:          Hit(Dud)    Miss        Miss        Miss
Erratic:              No          Yes         No          No
Mark Torpedo:         14-3A       14-3A       14-3A       14-3A
Serial No:            64141       40281       26135       24317
Mark Exploder:        6-4         6-4         6-5         6-4
Serial No.            11546       3528        25407       11534
Actuation Set:        Impact      Impact      Impact      Impact
Actuation Actual:     None        None        None        None
Mark Warhead:         16-1        16-1        16-1        16-1
Serial Number:        19471       19501       18276       5876
Explosivo:            Torpex      Torpex      Torpex      Torpex
Firing Interval:--                 13 Sec.     10 Sec.     77 Sec.
Typo Spread:          MOT         200 ft.     200 ft.     MOT
                                  left.       Right
Sea Condition:        2           2           2           2
Overhaul activity: 1. USS HOLLAND; 2. USS PROTEUS; 3. USS PROTEUS; 4. USS HOLLAND.
Miss Due to:          Dud         Erratic.    Spread.     Target Maneuvers.
                                  Run.

-25-                                                    ENCLOSURE(A)

— page 156 —
CONFIDENTIAL: U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol.
(H) ATTACK DATA (CONT'D) TORPEDO ATTACK NO. 2 PATROL NO. ELEVEN

REMARKS:

This target was tracked after SJ radar contact at 62,000
yards until moment of firing, a period of 5 hours and 16 minutes,
during which target's course and speed checked exactly on 285°(T),
8 knots. Although darkness was approaching, a submerged attack was
accepted, (a) in order not to delay the attack, (b) in order to id-
entify the target, (c) to facilitate firing stern tubes in order to
clear a tube aft for other uses. A torpedo run of about 800 yards was
intended, but 1500 yards occurred through inability to make out angle
in evening twilight.

At the instant of firing, all target data was known exactly.
The constant bearing method of firing was used with torpedoes aimed
at MOT, bow, stern, and MOT. At time of run 63 second for first
torpedo, all hands distinctly heard thud of a dud hit or low order
explosion. About same time heard whine of a circular run, believed
to be second torpedo, pass close to conning tower. Flooded negative
and started deep to avoid wild torpedo. At time of 69 seconds run
on third torpedo, several men reported sound as of another dud hit
or low order explosion. Was watching for wild torpedo through peris-
cope and did not observe any hits in target.

Sound conditions were bad and not much data is obtainable
from sound. JP and QB heard nothing. JK was occupied following the
circular run.

The fourth torpedo was fired at MOT when it was believed that
the first three were not producing the desired results. The TDC still
checked on, but it is believed target maneuvers caused this torpedo
to miss.

It is felt that target was damaged and perhaps sank. It is
hoped that information from other sources, perhaps from BOFFIN,
who was not too far distant, will determine the results of this
attack.

-26- ENCLOSURE (A)

— page 157 —
CONFIDENTIALL
U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol.
(H) ATTACK DATA (CONT'D)

TORPEDO ATTACK REPORT

U.S.S. TINOSA (SS283) Torpedo Attack No.3. Patrol No. ELEVEN.
Time: 0602(I) Date: 6/18/45 Latitude: 28°-23.5'N Longitude:128°-36'E
Description: Target appeared as an indistinct blob at
             11,000 yards in morning twilight. Apparent-
             ly had good length and a large superstruc-
             ture, or high freeboard. Not sighted again
             because of fog. Classified as unidentified.

Ship Sunk: None.

Ships Damaged or None.
Probably Sunk:

Damage Determined By: None.

Target Draft: Estimated very shallow.

OWN SHIP DATA

Speed: 3 knots Course: 220°(T) Depth: 17 feet Angle 1°Dive.

FIRE CONTROL AND TORPEDO
DATA

Type Attacks: Surface radar attack in fog: Target not
             seen.

-27-
ENCLOSURE (..)

— page 158 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol
(H) ATTACK DATA (CONT'D) TORPEDO ATTACK NO. 3. PATROL NO. ELEVEN.

| | 4 | 5 | 6 |
| :| :| :| :|
| Tube Fired: | | | |
| Zone Time: | 0602-22(I) | 0602-35(I) | 0602-97(I) |
| Range: | 700 yards | 700 yards | 700 yards. |
| Torpedo Run: | 500 yards | 500 yards | 500 yards. |
| Target Bearing: | 205°(T) | 205°(T) | 205°(T) |
| Track Angle: | 51° S | 54° S | 53° S |
| Gyro Angle: | 341 | 344 | 343 |
| Depth Set: | 6 feet | 6 feet | 6 feet |
| Power: | High | High | High |
| Hit or Miss: | Miss | Miss | Miss |
| Erratic: | No | No | No |
| Mark Torpedo: | 23 | 14-3A | 14-3A |
| Serial No: | 26848 | [HANDWRITTEN: 39984] | 40701 |
| Mark Exploder: | 6-5 | 6-5 | 6-5 |
| Serial N q: | 14134 | 25336 | 25137 |
| Actuation Set: | Impact | Impact | Impact |
| Actuation Actual: | None | None | None |
| Mark Warhead: | 16-1 | 16-1 | 16-1 |
| Serial Number: | 14626 | 3969 | 19455 |
| Explosive: | Torpex | Torpex | Torpex |
| Firing Interval: | -- | 13 sec. | 12 sec. |
| Type Spread: | MOT | 3° R | 3° L |
| Sea condition: | 2 | 2 | 2 |
| Overhaul activity: USS PROTEUS | USS PROTEUS | USS PROTEUS |
| Miss due to:Torpedo depth set too deep. | | |
| REMARKS: In view of excellent data, and firing position, it is be- | | |
| believed these torpedoes must have underrun a very shall | | |
| draft target. | | |

-28- ENCLOSURE (A)

— page 161 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report ELEVENTH War Patrol.
(H) ATTACK DATA (CONT'D)

TORPEDO ATTACK REPORT

U.S.S. TINOSA (SS283) Torpedo Attack No.5 Patrol No. Eleven.
Time: 0713(I) Date: 6/20/45. Latitude: 35°-39'N. Longitude: 130°-29'E.

TARGET DATA - DAMAGE INFLICTED

Description: Fox Tare Charlie similar to MAREI MARU,
4557 gross tons, (EC).

Ship Sunk: One FTC, similar MAREI MARU, 4557 Tons(EC).

Ships damaged or
Probably Sunk: None.

Damage Determined By: Watched target sink.

Target Draft: 15 Feet.

OWN SHIP DATA

Speed: 2 Course: 030 Depth: 66 feet Angle: 10 Dive.

FIRE CONTROL AND TORPEDO
DATA.

Type attacks: Submerged periscope attack using constant
bearing method of firing. Ping range of 800
yards just before firing. Spread by periscope.

-31- ENCLOSURE (A)

— page 162 —
CONFIDENTIAL
U.S.S. INOSA(SS283) - Report of ELEVENTH War Patrol.
(H) ATTACK DATA (CONT'D). TORPEDO ATTACK NO. 5. Patrol No. ELEVEN

| | 1. | 2. | 3.
Tube Fired: | | |
Zone Time: | 0712-52(I) | 0713-03(I) | 0713-18(I)
Rang e: | 850 yards | 700 yards | 600 yards.
Torpedo Run: | 750 yards | 600 yards. | 500 yards.
Target Bearing: | 005°(T) | 010°(T) | 010°(T).
Track Angle: | 65° S | 65.5° S | 74.5° S.
Gyro Angle: | 335. | 334.5 | 345.5
Depth Set: | 6 feet | 6 feet | 6 feet
Power: | High | High | High
Hit or Miss: | Hit | Hit | Hit
Erractic: | No | No | No
Mark Torpedo: | 14-3A | 14-3A | 14-3A
Serial No. | 63501 | 63525 | 26027
Mark Exploder: | 6-4 | 6-4 | 6-5
Serial N o: | 11535 | 8831 | 26674
Actuation Set. | Impact | Impact | Impact
Actuation Actual: | Impact | Impact | Impact
Mark Warhead: | 16-1 | 16-1 | 16-1
Serial Number: | -- | -- | 20945
Explosive: | Torpex | Torpex | Torpex
Firing Interval: | -- | 11 sec. | 15 sec
Type spread: | MOT | 150 feet | 150 feet
| | | ahead | astern
Sea Condition: | 2 | 2 | 2
Overhaul Activity: | USS Holland | USS Holland | USS Proteus.
Miss Due to: | -- | -- | --

REMARKS: Very satisfactory. Explosions heard 25 seconds after firing
#1, 22 secs after firing #2, and 20 seconds after firing
#3.

-32-
ENCLOSURE (A)

— page 163 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol.
(H) ATTACK DATA: (CONT'D)

TORPEDO ATTACK REPORT

U.S.S. TINOSA (SS283) Torpedo Attack No. 6. Patrol No. ELEVEN.
Time: 1929(I) Date: 6/20/45 Latitude: 36°-04'N Longitude: 130°-26'E.

TARGET DATA - DAMAGE INFLICTED

Description: Fox Tare Charlie, similar to HOKUAN MARU, 3712
gross tons(EC).

Ship Sunk: Fox Tare Charlie, similar to HOKUAN MARU, 3712
gross tons(EC).

Ships Damaged or None.
Probably Sunk:

Damage Determined By: Watched Target sink.

Target Draft: 15' Course: 109 Speed: 7.5 knots Range: 1400 yard

OWN SHIP DATA

Speed: 3 knots. Course: 180 Depth: 65' Angle 1° Dive.

FIRE CONTROL AND TORPEDO
DATA

Type attack:/ Submerged periscope attack. Used constant bearing
method of firing. Spread by periscope. Attempted
ping rangebut QC would not key.

-33- ENCLOSURE (A)

— page 164 —
CO FIDENTIAL U.S.S. TINOSA (SS283) - Report of Eleventh War Patrol.
(H) ATTACK DATA (CONT'D) Torpedo Attack No.6 Patrol No. ELEVEN.

| | 2 | 3 | 4 | 5 |
|---|---|---|---|---|
| Tube Fired: | | | | |
| Zono Time: | 1928-18(I) | 1928-30(I) | 1928-43(I) | 1929(I) |
| Range: | 1400 yds. | 1400 yds. | 1400 yds. | 1400 yds. |
| Torpedo Run: | 1200 yds. | 1200 yds | 1200 yds | 1200 yds. |
| Target Bearing: | 175°(T) | 177°(T) | 179°(T) | 180°(T) |
| Track Angle: | 103° P | 107° P | 112.5° P | 109° P. |
| Gyro Angle: | 357 | 353 | 347.5 | 351 |
| Depth Set: | 6 foot | 6 foot | 6 foot | 6 foot |
| Power: | High | High | High | High |
| Hit or Miss: | Hit | Hit | Miss | Miss |
| Erratic: | No | No | No | No |
| Mark Torpedo: | 23 | 14-3A | 14-3A | 14-3A |
| Serial No: | 65471 | 40726 | 26742 | 63691 |
| Mark Exploder: | 6-5 | 6-4 | 6-5 | 6-5 |
| Serial No: | 25619 | 2478 | 25606 | 11506 |
| Actuation Set: | Impact | Impact | Impact | Impact |
| Actuation Actual: | Impact | Impact | None | None |
| Mark Warhead: | 16-1 | 16-1 | 16-1 | 16-1 |
| Serial No: | 15521 | -- | 19528 | 11966 |
| Explosive: | Torpox | Torpex | Torpex | Torpex |
| Firing Interval: | -- | 12secs | 13 secs | 17 secs. |
| Type Spread: | 50' forward | 50' Aft | 200' ahead | 200'Ft. |
| | MOT | MOT | MOT | Aft.MOT |
| Sea Condition: | 2 | 2 | 2 | 2 |
| Overhaul Activity: | USS Proteus | USS Holland | USS Proteus | USS Proteus. |
| REMARKS: | First explosion heard 47 seconds after firing tubo #2; | | | |
| | second explosion heard 12 seconds later. | | | |

-34- ENCLOSURE (..)

— page 169 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol
(L) RADIO

Communications throughout the patrol were excellent. Sub-
marine fox schedules were copied easily, and a copy of the re-
ceiving log of that circuit is submitted in another report. The
advent of the CQM was gratifying, and all messages directed to
submarines were broken without hesitation.

Surplus frequencies are still being used to the optimum,
by both the enemy and ourselves. The only assurance of getting
a message through is to be close enough to the other boat so
that he can hear your signal over all the others. An average
of two contact reports were received nightly on this circuit from
aircraft, but the contacts were never in our vicinity.

The SCR-610 was manned at all times while on the surface.
Japanese CW and Japanese voices were intercepted, the latter,
seemingly, when we had probable aircraft contacts. On one occa-
sion, when an unidentified plane had just been sighted, an Eng-
lish speaking voice, very loud and clear, using improper pro-
cedure was heard. We had no knowledge of American aircraft us-
ing the frequency, and this fact, combined with the improper
procedure, seems to indicate that it was an English-speaking
Japanese. With subs in close proximity of each other the SCR-610
is a valuable aid. But, as on all voice circuits, the transmissi
were excessive, and mainly in plain language.

During the hunt for ten downed aviators, and at which
time a dense fog prevailed, we picked up their distress signal
twice, but were unable to act upon it. We knew they were in the
near vicinity, and could tell, with difficulty, if we were getti
closer by the increase in the signal strength. Planes circling
overhead were continually telling us that they were homing on
the distress signal, and it was a disheartening feeling to know
we could not do the same. The survivors ultimate rescue was de-
layed about seven hours, simply because we could not do the
signal. Subs are doing an increasing amount of sea-rescue work,
and the scene of action is slowly moving further north, where
continued inclement weather will be met. A radio direction
finding antenna should prove of value in such work.

For a period of a few days during the patrol, we were
required to guard the aircraft frequency 3145 kcs. During that
time the circuit was completely filled with enemy transmissions.
It is doubtful if we could have cleared a message on this fre-
quency, had it been necessary.

-39-
ENCLOSURE (A)

— page 171 —
_CONFIDENTIAL_
U.S.S. TINOSA (SS283) - Report of ELEVENTH War Patrol.
(N) _SOUND GEAR AND SOUND CONDITIONS._

Sound conditions in the Sea of Japan were definitely very
poor. The large negative gradients found were probably respon-
sible for the inability of the sound gear to pick up contacts
except at very close ranges.

It was discovered early in the patrol that JP and JK were
unable to pick up screws until the range had closed to less
than a thousand yards. Many tests were given the sound gear to
determine if the fault existed withing the gear itself. These
tests indicated all sound gear to be functioning properly,
leaving sound conditions as the most probable cause for poor
reception. No important material failures with any sound gear
were experienced.

The XQLM gear gave results that were comparable with those
obtained during operations prior to the beginning of the patrol.
Our spare sine pot and reversing relay had to be used in place
of those in the unit. The spare sine pot that was installed was
a used one, and in poor condition at the start, so it is desired
that two new ones be supplied us. The reversing relay that was
removed must be rebuilt.

Resistance measurements of the projector head for the XQLM
indicate a resistance of 40,000 ohms which is far below what
it should read, namely 10 megohms. It is very probable that
excessive moisture in the head is responsible for the low read-
ing; therefore, it is requested that a new head be installed
during refit.

-42- ENCLOSURE (A)

— page 175 —
SUBMARINE DIVISION ONE HUNDRED THREE.

FB5-103/A16-3                                Care of Fleet Post Office,
                                            San Francisco, California
Serial: 047                                 7 July 1945

C-O-N-F-I-D-E-N-T-I-A-L

FIRST ENDORSEMENT to
U.S.S. TINOSA (SS283)
Report of Eleventh War Patrol.

From:        The Commander Submarine Division ONE HUNDRED THREE.
To   :        The Commander in Chief, United States Fleet.
Via  :  (1) The Commander Submarine Squadron TEN.
        (2) The Commander Submarine Force, Pacific Fleet,
            Administration.
        (3) The Commander in Chief, U.S. Pacific Fleet.

Subject:     U.S.S. TINOSA (SS283) - Report of Eleventh War
            Patrol.

1.    The eleventh war patrol of the U.S.S. TINOSA,
under the command of Commander R.C. Latham, was conducted in
the Japan Sea during the period 29 May 1945 to 4 July 1945.
Nineteen (19) days were spent in the area.

2.    Contacts were numerous especially with fishing
vessels, and most of the contacts were small enemy merchant-
men or sea trucks. Six (6) aggressive torpedo attacks were
conducted and one brilliant gun attack. Besides the attacks
made, the TINOSA, by intelligent use of flares, the ship's
whistle and radar, and with the assistance of friendly planes,
successfully recovered ten survivors from a ditched B29 on
2 June 1945. These survivors were transferred to the
SCABBARDFISH on June 4th.

TORPEDO ATTACK NO. 1 - This was a daylight submerged
approach on 9 June 1945, on a heavily loaded SCL.
Three torpedoes were fired, one of which hit, and the
target was seen to sink.

TORPEDO ATTACK NO. 2 - On June 10th the TINOSA made
radar contact at the extreme range of 62,000 yards and
an end around run was made covering a period of over
five hours, during which time the target's course and
speed checked exactly. After gaining position the
Commanding Officer attacked submerged firing three
stern torpedoes. One hit was definitely a dud, one a
circular run which forced the TINOSA to deep submerg-
ence, and the third probably missed although there is
evidence that this torpedo was another dud. It is
unfortunate that after three plus years of war, our
torpedoes are still not entirely satisfactory. It is
understood that the BOWFIN probably sank this valuable
AK later on.

-1-

— page 177 —
SUBMARINE SQUADRON TEN
Fleet Post Office
San Francisco, California
7 July 1945

FC5-10/A16-3
11/rhb
Serial: 0154

C-O-N-F-I-D-E-N-T-I-A-L

SECOND ENDORSEMENT to
U.S.S. TINOSA (SS283)-
Report of War Patrol
Number Eleven.

From: The Commander Submarine Squadron TEN.
To : The Commander-in-Chief, UNITED STATES FLEET.
Via : (1) The Commander Submarine Force, PACIFIC
FLEET, Administration:
(2) The Commander-in-Chief, U.S. PACIFIC FLEET.

Subject: U.S.S. TINOSA (SS283) - Report of War Patrol
Number Eleven.

1. Forwarded, concurring in the remarks of the
Commander Submarine Division ONE HUNDRED THREE.

2. The Commander Submarine Squadron TEN takes great
pleasure in congratulating the Commanding Officer, officers
and crew of the U.S.S. TINOSA upon the high degree of courage
and skill shown in the successful completion of this difficult
patrol, which will live long in the annals of submarine warfare.

3. It is recommended that the U.S.S. TINOSA be
credited with the following:

SUNK
1 - SCL(EC) 2300 tons
1 - FTC(EC) (MAREI MARU type) 4557 tons
1 - FTC(EC) (HOKUAN MARU type) 3712 tons
1 - Sea Truck (EC) (Type E-2 modified) 1500 tons
Total sunk 12069 tons

DAMAGED
1 - AK(EU) 4000 tons
Total damaged 4000 tons

Total sunk and damaged 16069 tons

[SIGNATURE: G. E. Peterson]
G. E. PETERSON.

— page 178 —
[HANDWRITTEN: F-4253]
7 04758
[HANDWRITTEN: mr]
FF12-10(A)/A16-3(18) SUBMARINE FORCE, PACIFIC FLEET

Care of Fleet Post Office,
San Francisco, California,
16 July 1945.

Serial 01771

CONFIDENTIAL

THIRD ENDORSEMENT to
TINOSA Report of
Eleventh War Patrol.

NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.

COMSUBSPAC PATROL REPORT NO. 815
U.S.S. TINOSA - ELEVENTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To : The Commander in Chief, United States Fleet.
Via : The Commander in Chief, U. S. Pacific Fleet.

Subject: U.S.S. TINOSA (SS283) - Report of Eleventh War Patrol
(29 May to 4 July 1945).

1. The eleventh war patrol of the TINOSA, under the com-
mand of Commander R. C. Latham, U.S. Navy, was conducted in the
western section of the Japan Sea off the eastern coast of Korea.
The TINOSA, U.S.S. BOWFIN, and U.S.S. FLYING FISH formed a coordi-
nated attack group with the commanding officer of the FLYING FISH as
group commander.

2. This outstanding, highly successful patrol resulted in
numerous enemy contacts, which the TINOSA, in an expert and aggres-
sive manner, attacked at every opportunity. Six torpedo attacks and
one brilliant gun attack were made. Torpedo performance, including
two possible duds, was in some instances disappointing; however, four
enemy ships sunk and one damaged is a performance of which the TINOSA
can be very proud and a loss which the enemy can ill afford. In ad-
dition to this major blow to the enemy, the TINOSA had the pleasure
of rescuing ten survivors from a ditched B-29.

3. Award of Submarine Combat Insignia for this patrol is
authorized.

4. The Commander Submarine Force, Pacific Fleet, takes
great pleasure in congratulating the commanding officer, officers,
and crew of the TINOSA for this highly successful patrol. The daring
and skill required of each officer and man in this accomplishment is
deserving of the greatest praise. The TINOSA is credited with hav-
ing inflicted the following damage upon the enemy during this patrol:

S U N K

1 - Small AK (SCL Type) (EC) - 2,300 tons (Attack No. 1)
1 - Medium AK (MARIE Maru Type)(EC) - 4,600 tons (Attack No. 5)
1 - Medium AK (HOKUAI Maru Type)(EC)- 3,700 tons (Attack No. 6)
1 - SMC (Sea Truck Type E-2 Modi-
fied) (EC) - 1,500 tons (Gun Attack No. 1)
TOTAL SUNK 12,100 tons

EXTRA : ORIGINAL
SORG. MICRO
PHOTO-LAB OP-16
RETURN TO F-4253

- 1 -

— page 179 —
```
FF12-10(A)/416-3(18) SUBMARINE FORCE, PACIFIC FLEET mr
Serial 01771 js
Care of Fleet Post Office,
San Francisco, California,
CONFIDENTIAL 18 July 1945.
THIRD ENDORSEMENT to
TINOSA Report of
Eleventh War Patrol.
NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.
COMSUBSPAC PATROL REPORT NO. 815
U.S.S. TINOSA - ELEVENTH WAR PATROL.
Subject: U.S.S. TINOSA (SS283) - Report of Eleventh War Patrol
(29 May to 4 July 1945)

— page 180 —
[STAMP: CONFIDENTIAL]
[STAMP: DECLASSIFIED]
[STAMP: SDE 3/A16]
Serial: (129)

U.S.S. TINOSA (SS283)

Care of
Fleet Post Office
San Francisco, California
16 AUGUST, 1945.
[STAMP: DECLASSIFIED-ART. 0445, OPNAVINST 5510.1C]
BY [HANDWRITTEN: J.D.G. Mix] DATE [HANDWRITTEN: 6/20/77]

From: The Commanding Officer.
To : The Commander in Chief, UNITED STATES FLEET.

Via : (1) Commander Submarine Division ONE HUNDRED
FORTY TWO.
(2) Commander Submarine Squadron FOURTEEN.
(3) Commander Submarine Force, PACIFIC FLEET.

Subject: U.S.S. TINOSA (SS283) - Report of TWELFTH
War Patrol.

Enclosure: (A) Subject Report, (no track chart submitted).

1. Enclosure (A), covering the TWELFTH War Patrol
of this vessel in the Pacific Ocean during the period 11
August, 1945 to 16 August, 1945, is forwarded herewith.

[SIGNATURE: R.C. Latham]
R.C. LATHAM

[HANDWRITTEN: FILMED]
[HANDWRITTEN: 138976]

— page 181 —
U.S.S. TINOSA (SS283)
REPORT OF T.ELFTH WAR PATROL

CONFIDENTIAL
(A) PROLOGUE

     Arrived submarine Base, Pearl Harbor, T.H., from ELEVENTH
War Patrol on 4 July, 1945. Completed twenty-one day refit
conducted by SubDiv 103 and Submarine Base on 25 July, 1945.
Major work accomplished included installation of SD-5 radar,
shifting QB sound head to keel mount with installation of TD,
shifting JK-QC sound head to topside, installation of whip
antenna, installation of numerous mine cable clearing devices,
removal and straightening of starboard shaft, and removal of
20 MM gun forward and addition of 40 MM gun in its place.
Conducted special tests and training from 28 July, 1945, to
8 August, 1945 firing fifteen exercise torpedoes. Ready for
sea on 11 August, 1945.

-1-

— page 182 —
U.S.S. TINISA (SS283)
REPORT OF TWELFTH WAR PATROL

CONFIDENTIAL
(3) NARRATIVE

Transferred Lieut. (jg), B.S. WEAVER, USNR and Lieut. (jg)
G.F. SALISBURY, USNR. Reported aboard for duty: Lieutenant R.V.
SETTERSTROM, USNR, and Ensign W.N. SHELLER, USNR.

The following Officers and Chief Petty Officers were
attached and serving on board with number of patrols, including
present patrol, as indicated.

OFFICERS
NAME | RANK | NO. PATROLS
LATHAM, Richard C. | Comdr., USN | 6
SMITH, Harvey J., Jr. | Lt-Cdr., USN | 6
SETTERSTROM, Robert V. | Lieut., USNR | 1
SANDERS, Charles R. | Lieut., USNR | 5
BROOKS, Frank C. | Lieut., USNR | 9
GROSE, Herschel C. | Lt. (jg), USNR | 6
SIEGFRIED, Clyde W. | Lt. (jg), USN | 7
OLSEN, John (n) | Lt. (jg), USNR | 5
CLUTTERHAM, David R. | Ensign, USNR | 5
SHELLER, Willard N. | Ensign, USNR | 1

— page 183 —
U.S.S. TINOSA (SS283)
REPORT OF TWELFTH WAR PATROL

CONFIDENTIAL
(B) NARRATIVE CON'T

11 AUGUST, 1945

1330 (VW) Underway from Submarine Base, Pearl Harbor, T.H.,
for TWELFTH War Patrol, in company with escorts, PC 781 and
PC 817.

1645 (VW) Submerged for trim.

1719 (VW) Surfaced.

1815 (VW) Joined by U.S.S. CREVALLE.

2020 (VW) Released escorts.

2344 (VW) Two unidentified radar contacts passed well clear.

12 AUGUST, 1945

1200 (W) POSIT Lat. 20-48N, Long. 162-29W.

1514 (W) Passed ship's empty life raft.

13 AUGUST, 1945

Conducted daily radar tracking and submerged approach on
U.S.S. CREVALLE while in her company.

0925 (W) Submerged.

0956 (W) Surfaced.

1200 (X) POSIT Lat. 20-58N, Long. 168-09W.

14 AUGUST, 1945

0921 (X) Submerged.

0956 (X) Surfaced.

1200 (X) POSIT Lat. 21-15N, Long. 173-14W.

1210 (X) Received broadcast by President TRUMAN that Japan
had surrendered unconditionally.

-3- ENCLOSURE (B)

— page 184 —
U.S.S. TINOSA (SS283)
REPORT OF TWELFTH WAR PATROL

CONFIDENTIAL
(B) NARRATIVE CON'T

15 AUGUST, 1945
0045 (Y) Received orders directing TINOSA proceed MIDWAY.
0542 (Y) Sent TINOSA first requesting MIDWAY rendezvous.
1200 (Y) POSIT Lat. 23-42N, Long. 176-58E.
1800 (Y) Avoided unidentified ship contact without being
detected.

16 AUGUST, 1945
0640 (Y) Made rendezvous with plane escort.
0922 (Y) Moored MIDWAY.

(c) WEATHER
Fair throughout.

-4-

— page 185 —
U.S.S. TINOSA (SS283)
REPORT OF TELFTH WAR PATROL
CONFIDENTIAL

(D) TIDAL INFORMA
No remarks.

(E) NAVIGATIONAL AIDS
No remarks.

(F) SHIP CONTACTS
No enemy shipping encountered.

(G) AIRCRAFT CONTACTS
None

-5-

— page 186 —
U.S.S. TINOSA (SS283)
REPORT OF TWELFTH WAR PATROL
CONFIDENTIAL

(H) ATTACK DATA
     No attcks made.

(I) MINES
     No mines encountered.

(J) ANTI SUBMARINE MEASURES AND EVASION TACTICS
     None encountered.

(K) MAJOR DEFECTS AND DAMAGE
     All defects were of a very minor nature and were capably
     handled by ship's force.

(L) RADIO
     No remarks.

- 6. -

— page 187 —
U.S.S. TINOSA (SS283)
REPORT OF TELFTH WAR PATROL

CONFIDENTIAL
(M) RADAR
     No remarks.

(N) SOUND GEAR & SOUFD CONDITIONS
     No remarks.

(O) DENSITY LAYERS
     None encountered.

(P) HEALTH, FOOD AND HABITABILITY
     Health and habitability were excellent.
     Food was generous, variety adequate, and was at all times
well prepared.

-7-

— page 188 —
U.S.S. TINOSA (SS283)
REPORT OF TWELFTH WAR PATROL

CONFIDENTIAL
(Q) PERSONNEL

The performance of duty of each officer and man was at
all times exemplary. The mental strain caused by remors of
imminent peace was not a major factor for consideration. There
was no let down in alertness or attention to duty. The obvious
attitude throughout the ship was, "If it's over 'Thank God', if
it's not over, 'Let me get at 'em once more and soon.

Number of men detached after previous patrol10
Number of men on board during patrol75
Number of men qualified at start of patrol60
Number of men qualified at end of patrol60
Number of unqualified men making their first patrol-- 6

1

(R) MILES STEAMED

Pearl Harbor to Midway1544 miles

-8-

— page 189 —
U.S.S. TINOSA (SS283)
REPORT OF TWELFTH WAR PATROL

CONFIDENTIAL
(T) FACTORS OF ENDURANCE REMAINING
    Torpedoes----21 Mk XIV
                2 Mk XXVII
                2 Mk SSVIII
    Fuel97,446 gallons
    Provisions--75 days
    Personnel---70 days

    This patrol terminated by dispatch orders when Japan
    surrendered unconditionally.

(U) COMMUNICATIONS, RADAR AND SONAR COUNTERMEASURES

    No remarks.

(V) REMARKS

    Each officer and man feels the greatest pride that TINOSA
    was at sea on her TWELFTH War Patrol when Japan surrendered
    unconditionally. It is felt that no war patrol in this ship's
    history has been more successful.

-9-

— page 190 —
FB5-142/A16-3
Serial: 027
C-O-N-F-I-D-E-N-T-I-A-L
FIRST ENDORSEMENT to
TINOSA Twelfth War
Patrol Report.

SUBMARINE DIVISION 142
Fn
Care of Fleet Post Office,
San Francisco, California,
19 August 1945.

From: The Commander Submarine Division ONE FORTY-TWO.
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander Submarine Squadron FOURTEEN.
(2) The Commander Submarine Force, Pacific Fleet,
Administrative Command.
(3) The Commander-in-Chief, U.S. Pacific Fleet.
Subject: U.S.S. TINOSA (SS283) - Report of War Patrol
Number TWELVE.

1. The twelfth war patrol of the U.S.S. TINOSA was of
only six days duration, all of which were spent enroute to the
forward areas.

2. This patrol was terminated by the unconditional sur-
render of the Japanese Forces on 14 August 1945, and a subsequent
despatch from ComSubPac directing the TINOSA to MIDWAY, T.H.

3. The Division Commander takes this opportunity to con-
gratulate the Commanding Officer, officers and crew of the TINOSA
on their outstanding record of achievement during this war. Except
for a short period spent life guarding off TRUK, every patrol of
this submarine has been a successful one, and all have been character-
ized by intelligent planning and outstanding aggressiveness. To all
who contributed directly or indirectly to the fighting TINOSA's
outstanding record, is extended a sincere and thoroughly deserved
"Well Done".

[SIGNATURE: D.L. Wheel]
D.L. WHEEL.

— page 191 —
SUBMARINE SQUADRON FOURTEEN

FC5-14/A16-3
Serial: 0101
CONFIDENTIAL
20 August 1945

SECOND ENDORSEMENT to
TINOSA Twelfth War
Patrol Report.

From: The Commander Submarine Squadron FOURTEEN.
To: The Commander-in-Chief, United States Fleet.
Via: (1) The Commander Submarine Force, Pacific Fleet,
         Administration.
     (2) The Commander-in-Chief, U.S. Pacific Fleet.

Subject: U.S.S. TINOSA (SS283) - Report of War Patrol
         Number TWELVE.

1. Forwarded, concurring in the remarks of the
Commander Submarine Division ONE HUNDRED FORTY-TWO.

2. The Squadron Commander congratulates the
Commanding Officer, Officers and Crew of the TINOSA, whose
record of ten successful war patrols is deserving of highest
praise.

[SIGNATURE: (illegible handwritten signature)]
H. C. FISH.

Copy to:
Comsubdiv-142
TINOSA

— page 192 —
FF12-10(A)/A16-3(18 SUBMARINE FORCE, PACIFIC FLEET ld
Serial 02309 Care of Fleet Post Office,
San Francisco, California,
CONFIDENTIAL 15 September 1945.

THIRD ENDORSEMENT to
TINOSA Report of
Twelfth War Patrol. NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
COMSUBSPAC PATROL REPORT NO. 870 ENTERING PATROL AREA.
U.S.S. TINOSA - TWELFTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To : The Commander in Chief, United States Fleet.
Via : The Commander in Chief, U. S. Pacific Fleet.

Subject: U.S.S. TINOSA (SS283) - Report of Twelfth War Patrol
(11 August to 16 August 1945).

1. The U.S.S. TINOSA, under the command of Commander
R.C. Latham, U.S. Navy, departed on her twelfth war patrol but did
not reach her assigned patrol area prior to the time hostilities
with Japan were terminated.

2. This report is forwarded in order to complete the
war record of the U.S.S. TINOSA.

DISTRIBUTION: G. C. CRAWFORD,
(Complete Reports) Chief of Staff.
Cominch (7)
CNO (5)
Cincpac (6)
JICFOA (1)
AdICPOA (1)
Comservpac (1)
Cinclant (1)
Comsubslant (1)
S/M School, NL (8) [STAMP: EXTRA : ORIGINAL]
CO, S/M Base, PH (2) [STAMP: SORG. MICRO]
Comsopac (1) [STAMP: PHOTO-LAB OP-16]
Comsowespac (2) [STAMP: RETURN TO F-4253]
Comsubs7thFlt (Fwd Echelon) (1)
Comsubs7thFlt (Rear Echelon) (2)
Comnorpac (2)
Comsubspac (1)
ComsubspacAdComd (3)
SUBAD, MI (20)
All Squadron and Div. (2)
Commanders, Pacific (2)
ComSubOpTraGrBalboa (airmail) (5)
Substrainpac (2)
All Submarines, Pacific (1)
[SIGNATURE: E. L. Hynes] [HANDWRITTEN: (und)]
E. L. HYNES, 2nd.,
Flag Secretary.

10 0192

— page 193 —
A 1 12, 1946

MEMORANDUM BY OP-23-E-2.

Letter (FF12-10(A)/A16-3(6), serial 3689 of 18 October 1945
from The Commander Submarine Force, Pacific Fleet, Administration, Subject;
Patrol Reports, cancellation of, --- ordered that this War Patrol Report
be destroyed by burning, stating that no further reference will be made
of it, inasmuch as the submarines either did not reach their assigned
areas, were en route to a refueling station or were en route toward
patrol station for too short a time.

However, the attached report has not been destroyed and it is
retained for historical purposes only.

J. W. McElroy.
[SIGNATURE: McElroy]

— page 194 —
END OF REEL
JOB NO. [HANDWRITTEN: AR-5794- R=1]

[Resolution Chart Numbers]
1.0
4.5
5.0
2.8
2.5
3.2
2.2
3.6
2.0
1.1
1.8
1.25
1.4
1.6

THIS MICROFILM IS
THE PROPERTY OF
THE UNITED STATES
GOVERNMENT

[Seal Text]
DEPARTMENT OF DEFENSE
UNITED STATES OF AMERICA

MICROFILMED BY
NPPSO-NAVAL DISTRICT WASHINGTON
MICROFILM SECTION

D-52254

— page 195 —
START OF REEL # 1
JOB NO. [HANDWRITTEN: F-108]
[HANDWRITTEN: TR-46-82]
[HANDWRITTEN: TINOSA (SS-283)]

|||| 1.0
|||| 1.1
|||| 1.25

|||| 4.5 |||| 2.8 |||| 2.5
|||| 5.0 |||| 3.2 |||| 2.2
|||| 5.6 |||| 3.6 |||| 2.0
|||| 6.3 |||| 4.0 |||| 1.8

|||| 1.4 |||| 1.6

OPERATOR [HANDWRITTEN: Debora]

DATE [HANDWRITTEN: 4-13-82]

THIS MICROFILM IS
THE PROPERTY OF
THE UNITED STATES
GOVERNMENT

[SEAL: DEPARTMENT OF DEFENSE]
[SEAL: UNITED STATES OF AMERICA]

MICROFILMED BY
NPPSO-NAVAL DISTRICT WASHINGTON
MICROFILM SECTION

REEL TARGET - START AND END
NDW-NPPSO-5210/1 (6-78)

— page 196 —
[HANDWRITTEN: NAS P95-56]

[HANDWRITTEN: TINOSA (SS-283)]
[HANDWRITTEN: WORLD WAR II REPORT FILE]

[HANDWRITTEN: ALL MATERIAL ON THIS REEL IS DECLASSIFIED]

[HANDWRITTEN: FOR DECK LOG JANUARY 1943-JUNE 1945 CONSULT]
[HANDWRITTEN: NATIONAL ARCHIVES WHICH HAS CUSTODY]

[HANDWRITTEN: 35MM]

— page 197 —
Division of Naval History
Ships' Histories Section
Navy Department

HISTORY OF USS TINOSA (SS 283)

With daring and dexterity, the Silent Service of the United States Navy
has established a record of achievement and meritorious action of which few
units of any navy may boast. Stories of submarine heroism are legion. One
such story is that of the brilliant career of the submarine TINOSA. Already
decorated with nine Battle Stars, she received the nation's highest award
the Presidential Unit Citation for her fourth, fifth, and sixth war patrols.
However, her greatest contribution to the ultimate defeat of Japan was not in
terms of Japanese shipping sunk, for it was the TINOSA who tracked down and
cornered the defect in the Mark 6 torpedo.

Construction of the submarine began with the laying of the keel on 21
February 1942 at the Navy Yard, Mare Island, California. At the launching on
7 October 1942, Mrs. William E. Malloy, wife of Captain W. E. Malloy, USN,
wielded the traditional champagne bottle. Three months later on 15 January
1943, the USS TINOSA was accepted by the Navy and turned over to her command-
ing officer, Lieutenant Commander Lawrence R. Daspit, USN. The TINOSA was
named for a tropical black carongoid fish that is so poisonous that its sale
is forbidden.

The early months of 1943 were spent indoctrinating the crew in the ways
of submarine warfare and preparing for duty in the Pacific. On 16 April the
sleek submarine nosed into Pearl Harbor, ready to begin her prowl for trouble.
On 3 May she sailed on her first war patrol. The approaches to Kagoshima and
Nagasaki were now being continuously patrolled, and it was toward the coastal
waters of Kyushu that the TINOSA pointed her bow. Her first chance for action
came on 17 May. Fourteen torpedoes were fired for two hits in a 6,667 ton
freighter, damaging it severely. On 5 June a 10,936 passenger freighter was
damaged with two torpedoes, and on 10 June two more torpedoes damaged a large
tanker. On 19 June the TINOSA sped back to Midway.

She departed on her second patrol 7 July 1943 to be conducted in the
vicinity of Truk Island. The war would have been shortened and many American
lives saved had a reliable torpedo been available from the beginning. From
the first the submariners had been plagued by torpedoes running deep, prema-
turely firing, and failing to explode. By June 1943 most of the defects had
been corrected except that of failure to explode. The dud was a hard offender
to track down, but the TINOSA began to bring the trouble to light on 24 July
1943. On that date she had a chance to leisurely fire fifteen torpedoes at a
"sitting duck". The "sitting duck" was the TONAN MARU No. 3 - a prize coveted
by submarine captains. She and her sister ship the No.2, had been built as whale
factories for processing whales and rendering the blubber at sea. They had
later been converted into oil tankers for government use. With a gross tonnage
rating of 19,262 tons, each was a whale of a tanker. About twice the size of
the average merchant oil carrier, they were the largest tankers that Japan
possessed.

The TINOSA was patrolling westward of Truk when the giant tanker was
sighted, steaming nonchalantly across the horizon unescorted. The TINOSA closed

— page 198 —
-2- USS TINOSA (SS 263)

and opened fire on the tanker with a spread of four torpedoes. The
hit near the tanker's stern. The ship stopped dead in the water and veered
in a manner which placed the submarine about two points on her port quarter.
Two more torpedoes were quickly fired. Both exploded resoundingly. The TONAN
MARU No. 3 belched smoke and settled slightly by the stern. Here was a situa-
tion almost too good for verity -- the big ex-whale factory dead in the water
like a mired hippopotamus -- not an anti-submarine vessel in the vicinity --
submariners with plenty of time at their disposal to finish off the target at
will. The tanker's sizable deck guns prohibited a surface assault, but the
TINOSA closed in for a torpedo attack calculated to blow the helpless vessel
to blazes.

One torpedo was fired 875 yards off the tanker's beam. It was heard
to make a normal run. At the moment when the sound of the torpedo's screws
stopped abruptly, a splash at the point of aim was seen through the periscope,
but there was no explosion. Deliberately Commander Daspit lined the TINOSA
up for another attack, fired another torpedo. Again the torpedo's run trailed
off into silence. Two more torpedoes were fired with great care and precision.
If silence was golden the TINOSA had hit the jackpot. A blind man could not
have missed at that range, but the tanker remained fixed in the scene. Four
more torpedoes were fired. One was seen to hit the tanker, jump clear of the
water like a playful bass, and sink. The tanker sat there like the broadside
of a barn as the TINOSA pelted her with eight duds. The shooting lasted over
a period of several hours, ceasing when only one torpedo remained on board.
Fifteen torpedoes had been expended on a single target -- twelve hits -- and
the TONAN MARU No. 3 remained obdurately afloat.

Japanese rescuers raced out and towed the great tanker safely into Truk
while the disillusioned TINOSA headed home to Pearl Harbor. When she reached
Pearl Harbor on 4 August, a thorough examination of her remaining torpedo failed
to disclose any errors in adjustment. A series of tests then revealed that
Commander Daspit's careful and finely calculated selection of the best possible
track angle was his undoing. Had the torpedoes struck the target glancing blows,
as was the case with the first two salvos, the exploders might have worked. Fired
at a 90° angle, where by they struck the target squarely with normal impact,
they failed to work. The firing pin did not strike the primer cap with suffi-
cient force to set it off. Subsequent corrective measures developed a modified
firing pin, and on September 30th -- almost two years after the beginning of the
war -- U. S. submarines went to sea with a reliable torpedo.

Upon completion of refit the TINOSA departed Pearl Harbor on 24 September
1943 for her third patrol again in the vicinity of Truk. On 4 October she
damaged a 9525 ton tanker with two torpedo hits. Two days later she cornered
the tanker KAZAHAYA and with six torpedo hits, sent her down in a gush
of blazing oil. At sunset on the 7th, the TINOSA conducted a bombardment of Alet
Island of the Paluwat Group. Forty-one high capacity shells were fired, damag-
ing a small radio station. Her third war patrol ended as the sub pushed her way
into Submarine Base, Midway Island on 16 October 1943.

The ship departed for her fourth patrol on 27 October, and went out to
meet the enemy in the waters near Palau. Here, she was to stage a devastating
foray. North of Truk she made one contact on a MOGAMI-class cruiser. She

— page 199 —
-3- USS TINOSA (SS 263)

maneuvered into a favorable position ahead, but the target escaped by making a
couple of fortunate zigzags. November 15th the TINOSA was patrolling off
Toagel Mlungui, the western entrance to the Palau lagoon. The pass was well
guarded by surface patrols with air cover whenever any activity was pending.
Traffic bustled in and out of the pass. In three days the TINOSA made contact
with three convoys and several independent ships, including a small tanker and
a destroyer. Night chase of a merchant vessel spotted at sunset had ended when
the target materialized as a properly lighted hospital ship. On none of the
"legal" contacts had it been possible to obtain attack position. When the sub-
marine's speed was above 6 knots, a noise developed in the superstructure and
this was evidently sufficient to attract the alert patrols. She was depth-
charged on one occasion after trying a fast approach, and the surface patrol
was evidently addicted to the use of depth charges every now and now, with
or without submarine contact. Seeing that the enemy was now aware that a sub-
marine was off Toagel Mlungui, the TINOSA withdrew on the 18th to patrol along
the Palau-Molucca Passage track. On the 22nd she returned to the vicinity
of Palau, this time electing to cover Malakal Passage, the eastern entrance to
the lagoon.

At early dawn the presence of the usual channel-guarding surface patrol
was seen. No aircraft were sighted, and the TINOSA continued to patrol at
periscope depth, making a quick sweep every three minutes. At 0741 smoke was
sighted to the southeast, and the crew manned battle stations. As the target
was probably headed toward the passage through the reef, and as the TINOSA was
between the ship and its destination, there was no need for preliminary
maneuvers to establish direction of movement. Remaining at periscope depth,
the TINOSA headed directly for the target.

Seven minutes later the smoke was made out to be a convoy -- two freight-
ers in column with two escorts, one escort leading and one trailing. The con-
voy was zigzagging radically every four minutes, but the attack problem was
much simplified by the knowledge that the ships must be headed towards the
opening in the reef. The convoy's speed was 10 knots, and the approach which
had taken a little over an hour, had reached the attack stage. Having selected
a ship for the first target, Commander Daspit sent the TINOSA boring in. The
freighter made her last zig. The TINOSA came around to the course for a three
torpedo salvo from the stern tubes. Thirty seconds later she scored three
hits. The 7071 ton KISO MARU rolled over on her side and settled rapidly.
The escorts wheeled around like puzzled watchdogs. The TINOSA was swinging hard
right to bring the bow tubes to bear on the second freighter. It would have
been touch and go to get around in time had not the target made a wrong
maneuver and swung hard right rudder. At first glance it looked as if she
were going to ram, but she swung on by. By 0842 she steadied down, and was
directly in line for a straight bow shot. Two of the three torpedoes hit the
YAMATO MARU and left her going down by the stern.

The TINOSA was now between two sinking targets, with torpedo tracks
extending in both directions, making an "X" to mark the submarines' position.
She went deep, changing course as she did so, and the stunned escort vessels
failed to locate her.

— page 200 —
-4- USS TINOSA (SS 263)

The raider was still not ready to stop. On 26 November she revisited the
Toagel Mlungui neighborhood to sink the 3,811 ton Shini Maru. On December 3rd
she sent another warhead into the 6,464 ton passenger-cargomen AZUMA MARU.
When the TINOSA arrived at Darwin, Australia on 10 December to complete her
patrol, Japanese statisticians had subtracted some 18,000 tons of shipping from
the Palau merchant service.

After refueling at Darwin the submarine continued on to Fremantle,
Australia to join the South West Pacific Force. Here Commander D. F. Weiss,
USN, relieved Commander Daspit as commanding officer, and took the TINOSA out
for her fifth war patrol on 10 January of the new year 1944. As the new calendar
year opened, the United States had secured the Gilberts and was ready to un-
leash an offensive in the Central Pacific designed to obliterate or neutralize
Japan's Mandate bases and carry through to the Philippines. In support of this
operation the TINOSA was assigned an anti-shipping sweep in the South China
Sea for this patrol. It was conducted northwest of Borneo and in the southern
Philippines. She caught a convoy on 22 January; whereupon the Japanese lost
the KOSHEIN MARU, 5,401 ton passenger cargoman, and SEINAN MARU, 5,485 ton
freighter with one and two torpedo hits respectively. She succeeded in torpedo-
ing another freighter on 15 February, the ODATSUKI MARU. In the same action
the transport OJOJO MARU was damaged, and sank the following day. The TINOSA
ended her patrol on 4 March 1944 upon arrival at Pearl Harbor.

On 29 March 1944 the TINOSA sailed majestically out of Pearl Harbor for
her sixth war patrol. She was a member of a wolf-pack in company with the
PARCHE and BANG. Southwest of Japanese held Formosa in the Luzon Straits,
Japanese ships sailed to replenish and re-garrison their fast dwindling Pacific
bastions. The wolf-pack began their furtive hunt in this area on 16 April. For
two weeks the submarine trio skimmed through the Luzon Straits, at all times
keeping in close radio contact with one another in the event of worthwhile
target material. Late at night on 29 April the PARCHE contacted an 11-
ship convoy chugging south, and the submarines began the chase. All night
and well into the morning of the 30th the three subs tracked the fleeing ships.
In an unrelenting series of approaches, the TINOSA's torpedoes ripped two
freighters apart, and damaged one 7500 ton tanker.

The TINOSA sighted another convoy travelling north on the 3rd of May.
In the ensuing attack two torpedo hits were scored on a 10,500 ton tanker, and
two additional freighters were badly damaged. The next day she made another
successful attack on a 6440 ton freighter, TAIBU MARU, with three hits scored
from four torpedoes fired. After departing the area the sub sighted a large
trawler of 150 tons on the 9th, and sank it with gunfire. She ended her sixth
patrol on 15 May 1944 upon arrival at Majuro.

By 7 June 1944 the TINOSA was again ready for sea, and sailed for her
seventh war patrol in the East China Sea. On the 18th she sank a 400 ton
sailing vessel by gunfire, and on the 22nd a 50 ton sampan was demolished in
like manner. Hunting improved on 3 July when she contacted a convoy of freight-
ers. Six torpedoes were fired to score three hits on the 2,733 ton KONSAN MARU,
and two hits on the 7,954 ton KAMO MARU, sinking both. The final engagement
of this patrol came when the TINOSA destroyed a 100 ton trawler by gunfire on
10 July. She terminated her patrol on 30 July at Pearl Harbor.

— page 201 —
-5- USS TINOSA (SS 263)

There was a two-month interim between the seventh and eighth war patrols
as the submarine was given a thorough overhaul at the Naval Drydocks, Hunters
Point, California. During this period Commander D. F. Weiss was relieved by
Lieutenant Commander Richard C. Latham, USN.

The TINOSA departed Pearl Harbor for her eighth patrol on 4 December 1944
to be conducted in the Nansei Shoto-Formosa area. Due to the dearth of worth-
while targets, no torpedo attacks were made during this patrol. From 22
December 1944 to 9 January 1945 she conducted a particularly hazardous special
mission detecting mines in the empire area. She departed the area on 18
January, refueled at Midway on the 26th and arrived at Pearl Harbor on the 30th
to end the eighth patrol.

Following refitting the submarine departed Pearl Harbor 1 March 1945
enroute to Saipan. Special tests with sound equipment were conducted here
until the 17th, at which time she sailed in company with the SPADEFISH and the
TIRANTE for her ninth war patrol. On 23 March the TINOSA experienced consider-
able difficulty with the bow planes which made depth control at periscope depth
almost impossible. She transitted the Nansei Shoto at 150 feet, and from the
25th to the 27th conducted another special mine detection mission. On 28
March she took two Japanese prisoners aboard from a lifeboat containing seven-
teen. Due to the bow plane difficulty the TINOSA departed the area early and
returned to Guam on 7 April 1945.

A short training period followed the refit, and on 28 April she steamed
out of Guam on her tenth war patrol. She was assigned lifeguard duty in the
Truk vicinity. At 1626 on 3 May a Japanese "Jake" succeeded in getting almost
overhead before being noticed. One bomb landed about one hundred yards ahead
of the TINOSA. Little damage resulted, and the sub submerged before additional
attacks could be made. No opportunities presented themselves for rendering
lifeguard services, and the TINOSA returned to Guam on 16 May 1945.

Following a five day refit, the TINOSA sailed from Guam in company with
the FLYING FISH and BOWFIN. Until now the Japan Sea, heavily guarded with
minefields, had been out of bounds for submarines. Equipped with a new mine-
detecting device, these three submarines joined six more to form a group called
the "Hellcats", whose mission it was to penetrate the mine defenses and enter
the Sea of Japan for a surprise offensive against enemy shipping. Leaving
Guam on 27 May, the nine submarines headed northwestward, their bows pointing
like compass needles for Tsushima Strait. Enroute the ships performed life-
guard duties, and the TINOSA rescued 10 men of the crew of a B-29 which had
crashed about 18 miles northeast of Sofu Gan. The "Hellcats" crept through
Tsushima Strait and entered the Sea of Japan on schedule. Shooting was timed
to begin at sunset on 9 June. The overconfident Japanese were astounded by the
sudden thunder of torpedo fire off the west coast of Honshu. Shortly after
sunset the TINOSA torpedoed the 2,211 ton cargo ship, WAKATAMA MARU. She had
considerable difficulty with her own torpedoes next day, when one out of four fired
at a medium freighter, one missed, two failed to explode upon hitting the
target, and the other made a circular run and roared over the submarine. On
12 June she sank an 880 ton sea truck by gunfire. June 20th proved more pro-
ductive. Three torpedoes were fired for three hits on the 2,726 ton freighter
TAITO MARU, sinking her in thirty-five seconds. At 1924 on the same day the
small freighter, KAISEI MARU, was sunk in fifty seconds with two hits. In

— page 202 —
-6- USS TINOSA (SS 263)

accordance with plans, the submarines assembled off La Perouse Strait, and on
the night of 24 June, running on the surface through cotton-thick fog, began
their dash for the Pacific. Moving in parallel columns, and communicating by
voice radio, the "Hellcats" closed up and raced through the Strait at 18 knots.
Colors flying, they entered Pearl Harbor on the Fourth of July.

She steamed out of Pearl Harbor on 11 August to begin her twelfth patrol.
Before she reached her assigned area, news of Japan's capitulation was received,
and on 16 August 1945 the TINOSA returned to Midway. She began the long
trek home on 25 August, and just a few hours after sunrise on 4 September the
gallant ship passed under the Golden Gate Bridge to end her war career.

The USS TINOSA was awarded the Presidential Unit Citation with the text
of the citation reading as follows:

"For extraordinary heroism in action during her Fourth, Fifth
and Sixth War Patrols in the restricted waters of the Carolines
and the Philippines. Pursuing highly aggressive and tenacious
tactics while covering wide areas of her assigned sectors, the
USS TINOSA with penetrating air and surface escort
screens to strike at the enemy with well planned and brilliantly
executed gun and torpedo attacks. In ready response to the
urgency of each hazardous mission, she closed her targets
gallantly and dealt smashing blows at the enemy's supply in
destroying or damaging thousands of tons of shipping and material
vital to the maintenance of his war machine. A valiant fight-
ing ship, implementing the superb seamanship and skill of her
entire ship's company by her own unfailing fortitude under
relentless Japanese bombing, gunfire and depth-charging, the
TINOSA returned to port safe with an illustrious record of com-
bat achievement in keeping with the highest traditions of the
United States Naval Service."

She also received nine Battle Stars on the Asiatic-Pacific Area Service
Medal for participating in the following operations:

1 Star/Okinawa Gunto Operation
Assault and occupation of Okinawa Gunto -- 17 March - 21 June 1945

1 Star/First Submarine War Patrol -- 3 May - 19 June 1943

1 Star/Second Submarine War Patrol -- 7 July - 4 August 1943

1 Star/Third Submarine War Patrol -- 23 September - 16 October 1943

1 Star/Fourth Submarine War Patrol -- 27 October - 16 December 1943

1 Star/Fifth Submarine War Patrol -- 10 January - 4 March 1944

1 Star/Sixth Submarine War Patrol -- 29 March - 15 May 1944

1 Star/Seventh Submarine War Patrol -- 7 June - 30 July 1944

1 Star/Eighth Submarine War Patrol -- 4 December 1944 - 30 January 1945

— page 203 —
-7- USS TINOSA (SS 263)

The following officers and men have received awards for services per-
formed while on board the USS TINOSA:

Navy Cross

Commander Lawrence R. Daspit, USN
Commander Richard C. Latham, USN
Commander D. F. Weiss, USN

Legion of Merit

Commander Richard C. Latham, USN

Silver Star

Lieutenant Commander Harvey J. Smith, Jr., USN
Ensign D. R. Clutterham, USNR
William R. Clement, TM1c, USNR
Lieutenant Commander James L. Hunnicutt, USNR
Harold E. Connery, TM1c, USN
Elmir G. Stevison, MM2c, USNR
Lieutenant Clarence E. Bell, Jr., USN
Lieutenant (jg) Lawrence A. Beck, USNR
Albert O. Rusted, RM1c, USN

Bronze Star

Lieutenant (jg) Clyde W. Siefried, USN
Lieutenant (jg) John Olsen, USNR
Floyd C. Baird, CMOMM, USNR
Richard L. Dixon, TM1c, USN
Lieutenant Commander Harvey J. Smith, Jr., USN
Victor L. Stokes, CEM, USN
Lieutenant Commander Roger W. Paine, Jr., UNS
Freeman W. Welch, CTM, USN
Commander Donald F. Weiss, USN
Lieutenant (jg) Moritz J. Schroeder, USNR
Giuseppi O. Giuffrida, TM1c, USN
Clyde R. Lesh, EM 1c, USNR
Roy D. Harris, EM1c, USNR
Lieutenant William B. Robb, USN
Lieutenant (jg) Eldridge A. Erickson, USNR
Ensign Keith R. Van Gorder, USN
Charles F. Hunt, BM1c, USN
Elroy F. Wilke, CMOMM, USN

By Directive dated January 1947 the USS TINOSA was placed out of commis-
sion in reserve, berthed at Mare Island, California.

STATISTICS

OVERALL LENGTH           312 feet                 BEAM           27 feet
DISPLACEMENT             1475 tons                SPEED          20 knots
COMPLEMENT               8 officers and 72 men

Compiled: 28 December 1953

— page 204 —
DECLASSIFIED
DATE 20 January 1944
FROM Commanding Officer USSTINOSA (SS-283)
NAME TINOSA
SERIAL 1
DATE none
SUBJECT SPECIAL MISSION
Report (to CTG 71.1) of successful resupply mission to
Allied Intelligence personnel at Labian Point, northeast
Borneo. Mission carried out during FIFTH WAR PATROL.
(COMSUBPAC:SUB OPS)
FILED: War Diary
Separately as CARBON COPY; as DUPLICATE COPY

MICROSERIAL NO. | ACTION REPORT OPNAV FORM 38B0-13 (11-55)
| G20432

DATE 16 April-16 May 1944
FROM CROSS INDEX CARD
NAME TINOSA
SERIAL
DATE
SUBJECT Coordinated Patrol Report
Report of FOURTH Coordinated Attack Group under Capt.G.S.
Petersen in EAST CHINS ASE. Sank or damaged 116,100 tons
of enemy shipping.

FILED: War Diary
Separately under TASK GROUP 17.15 ser X-1 of 4 Jun 44

MICROSERIAL NO. | ACTION REPORT OPNAV FORM 38B0-13 (10-55)
| B.21013

DATE 22 Dec 44-12 Jan 45
FROM CO-USS TINOSA (SS-283)
NAME TINOSA
SERIAL 001
DATE 29 January 1945
SUBJECT SPECIAL MISSION REPORT
Report of operations in Nansei Shoto Islands especially
in Okinawa area during EIGHTH WAR PATROL to test FM
Sonar. Equipment tested to determine if it could locate
Japanese mines preparatory to use in Operation BARNEY.

FILED: War Diary
Separately as CARBON COPY
as Enc to SUBSPAC ser 00026 of 9 Apr 45

(CENPAC:SUB OPS)
MICROSERIAL NO. | ACTION REPORT OPNAV FORM 38B0-13 (10-55)
| B.21013

— page 205 —
DATE 25 March-2 April 1945
FROM Commanding Officer USS TINOSA (SS-283)
SUBJECT SPECIAL MISSION

Report (to SUBSPAC) of special FOX MIKE Sonar sweep for
minefields in the Nansei Shoto area of the East China
Sea during NINTH WAR PATROL.
(CENPAC: SUB OPS)
FILED: War Diary

Separately as CARBON COPY; as ORIGINAL

MICROSERIAL NO.

DATE 1-10 May 1945
FROM Commanding Officer USS TINOSA (SS-283)
SUBJECT SONAR Operations

Report of use of FOX MIKE SONAR during TENTH WAR PATROL
which was conducted in Truk area.

(CENPAC: SUB OPS)
FILED: War Diary

Separately as ORIGINAL

MICROSERIAL NO.

DATE 6-25 June 1945
FROM Commanding Officer USS TINOSA (SS-283)
SUBJECT Passage of TSUSHIMA Straits

Report of FOX MIKE SONAR operations during ELEVENTH WAR
PATROL. Submarine passed into and out of Japan Sea
6 and 25 June 1945.
(CENPAC: SUB OPS)
FILED: War Diary

Separately as ORIGINAL

MICROSERIAL NO. NAME TINOSA
SERIAL 0001
DATE 7 April 1945

ACTION REPORT OPNAV FORM 3480-13 (11-55)
G 20432

NAME TINOSA
SERIAL 0002
DATE 16 May 1945

ACTION REPORT OPNAV FORM 3480-13 (11-55)
G 20432

NAME TINOSA
SERIAL 0003
DATE 4 July 1945

ACTION REPORT OPNAV FORM 3480-13 (11-55)
G 20432 A

A

A

— page 206 —
[HANDWRITTEN: TSU]
[HANDWRITTEN: SWP] [HANDWRITTEN: 2]

U. S. S. TINOSA (SS 283)
Care of Fleet Post Office
San Francisco, California

[HANDWRITTEN: R5 332]
[STAMP: DECLASSIFIED - OPM NAV INST 5500.30]
[HANDWRITTEN: BY J.J. Kier DATE 4 Oct 60]

SS283/A14-5
Serial #1
[STAMP: DECLASSIFIED]
[STAMP: SECRET]

From: The Commanding Officer.
To : Commander Task Group SEVENTY-ONE POINT ONE.

Subject: Special Mission.

Reference: (a) Annex "Dog" to CTG 71-1 OPORD #5-44.

1. In accordance with reference (a) this vessel,
on the night of 9 January 1944, took aboard four (4) rubber
dinghies and five thousand (5,000) lbs of supplies for
Python Two. The members and their personal gear came aboard
prior to noon of the tenth, the Tinosa getting underway at
1310 the same day.

2. Prior to the above, I was informed of in-
adequate boat facilities on a previous mission and had the
opportunity to discuss this phase with the officers in charge
of Python Two. They informed me they were cognizant of the
prior difficulties and had thoroughly checked their present
equipment and found it more than adequate; in fact, twice as
much as they needed as far as boat capacity was concerned.

3. A special station bill was made up to facilitate
loading and launching of this party and its equipment. Each
person in this party was then instructed in his duties. After
fueling at Exmouth a full dress rehearsal was held in which
the boats were inflated, loaded with supplies, equipment, and
personnel, and launched by flooding down. The time and
arrangements for loading and launching were found satisfactory.
However, the four boats, though undoubtedly having sufficient
weight capacity, were definitely inadequate as to volume and
the Tinosa's boat was piled high with the remaining stores.

4. We arrived off Labian Point prior to dawn on
20 January 1944, and submerged, no signals having been seen
as yet. The day signal was spotted shortly after sunrise and
submerged reconnaissance of the coast for 7 to 8 miles either
side of this spot was made during the day. We turned in
toward the beach at 1645, rigged in the log and sound heads,
and at 1745 imperceptibly grounded about 600 yards off the
beach. Shortly after this one of the men on shore spotted our
periscope, waved frantically, called the others from the bush
and strutted up and down the small sandy beach waving a large
American Flag. (What if we had been a Jap?). We remained

[HANDWRITTEN: Com Sub For Pac Flt Box #A-5-600CRS # 32 FILE C.S. JACKET # A4-5]

- 1 -

— page 207 —
[HANDWRITTEN: TSG1]
[HANDWRITTEN: R5332]

SS283/A14-5
Serial #1
[STRIKETHROUGH: S-E-C-R-E-T]

U. S. S. TINOSA (SS 283)
Care of Fleet Post Office
San Francisco, California

Subject:

Special Mission.

submerged in this position until dusk about a half hour later,
surfaced, exchanged recognition signals, told them to come out,
and got all equipment topside and loaded as previously planned.
However, our plans were changed immediately upon the arrival
of the shore party in two native boats which were large enough
to take all the gear, so the small rubber boats were unloaded
and not used. It was a black night and the leader of the
party, Major Chester, assured us of our safety, so we took all
hands aboard for dinner. They ate like wolves. The officers
and crew pitched in and gave them a plentiful supply of
clothing and cigarettes, for which they were extremely grate-
ful. At 2020 they were headed for the beach, the entire
procedure having taken just two hours. Ten minutes later the
Tinosa was on its way, it's special mission successfully
completed.

D.F. WEISS.

[HANDWRITTEN: Bp]

— page 208 —
[HANDWRITTEN: Photostat (6)]

COMMANDER SUBMARINE DIVISION ONE HUNDRED FORTY-ONE

Care of Fleet Post Office,
San Francisco, California.
4 June 1944.

FB5-141/A16-3
Serial: (X-1)
[STAMP: DECLASSIFIED]

From: The Commander Task Group 17.15 (Comsubdiv 141).
To : The Commander-in-Chief, United States Fleet.
Via : (1) The Commander-in-Chief, U.S. Pacific Fleet.
(2) The Commander Submarine Force, Pacific Fleet.

Subject: War Patrol of Coordinated Attack Group 17.15 from
March 29, 1944 to May 23, 1944.

Reference: (a) Report of War Patrol #1, U.S.S. PARCHE.
(b) Report of War Patrol #1, U.S.S. BANG.
(c) Report of War Patrol #6, U.S.S. TINOSA.

Enclosure: (A) Subject War Patrol.
(B) Detailed Plan of Coordinated Patrol and Attack.

1. Enclosure (A), covering the subject War Patrol is herewith
submitted. This Task Group operated in the China Sea, south of Formosa.
References (a), (b) and (c) cover the detail activities of the individual
ships of Task Group 17.15. This narrative pertains only to that portion
of the patrol where the submarines operated as a Coordinated Attack Group.

2. The detail plan for the Coordinated Patrol and Attack was
prepared enroute to Midway and is submitted as enclosure (B).

G. E. PETERSON.

[HANDWRITTEN: (4)]

— page 218 —
DETAILED PLAN FOR COORDINATED PATROL AND
ATTACK FOR TASK GROUP 17.15

C-O-N-F-I-D-E-N-T-I-A-L
Enclosures: (A) Group Squares for Area Eleven (D).
(B) Coordinated Attack Doctrine.
(C) Submarine Coordinated Attack Code.

Rendezvous Points Enroute to Area

1. Enroute to area the sight rendezvous points listed below are
assigned according to the speed of advance of 12 knots up to Long. 164 E, then
9 knots. These rendezvous points are numbered consecutively and will commence
on the date after the day of departure. Time of rendezvous will be at sunset
and will be made on the center submarine (Parche). If, while enroute, a diver-
sion is made, the submarine will, without signal, make the next rendezvous point,
in the direction of advance, which they can make at two engine speed. There
will be no waiting at rendezvous points or reversal of course in case a point
is passed during the diversion.

2. In the event, a submarine becomes separated from the remainder
of the group, so that he will be unable to make the expected rendezvous with-
out excessive expenditure of fuel, he will send signal designating the number
of the position he can get to and the date. The Group Commander will then
attempt to meet the rendezvous or designate another.

3. Unless otherwise directed, there will be no rendezvous points
upon returning. Each submarine of the group will return independently.

4. Rendezvous points enroute to area.
Center submarine will be at following points:

GCT Rend. Point
0600/4 (1) 28 05 N 179 43 W
0600/5 (2) 27 41 N 174 55 E 12 knots
0700/6 (3) 27 20 N 169 20 E 288 miles daily
0700/7 (4) 27 21 N 163 54 E

0700/8 (5) 27 10 N 160 06 E
0700/9 (6) 26 48 N 156 16 E
0800/10 (7) 26 02 N 152 20 E
0800/11 (8) 25 12 N 148 37 E 8.83 knots
0800/12 (9) 24 19 N 144 55 E 212 miles daily
0900/13 (10) 23 25 N 141 05 E
0900/14 (11) 23 00 N 137 17 E
0900/15 (12) 22 30 N 133 27 E
1000/16 (13) 22 00 N 129 30 E

* 1 *
c o p y
ENCLOSURE (B)

[HANDWRITTEN: (14)]

— page 219 —
CONFIDENTIAL

Operating Doctrine in Area

1. Enclosure (A) shows the patrol area Eleven (D) divided into squares of
1° latitude and 1° longitude on a side. These squares are appropriately lettered.
In some cases it will be necessary to designate the square with a letter and
number. The center of the square will be the Group Position Point and all enemy
contacts will be referenced to this point.

2. Each square is divided into three smaller areas. The center of these
areas will be the 0000 G.C.T. positions of the respective ships on the prospect-
ive days; from which they will proceed to the next assigned position at speeds to
get them there at 0000 G.C.T. the next day. This movement usually keeps the ships
in column or an approximate line of bearing normal to the probable shipping
routes. It is to be noted that all the areas are not rectangles. In such areas
(traiangle), the flank submarines may patrol beyond the area limits but along
a lane parallell to the center lane. The ships should remain in their area s
in such positions that the flanking submarines be no more than 20 miles from
the track of the center ship; considering the center ship runs on a track through
the center of her area.

3. Unless otherwise directed the order of ships in column will be; Tinosa;
Parch, Bang. The line of bearing formation the Tinosa will patrol in the west
or north area of the square and the Bang will patrol in the east or south area
of the square. Parch will be in the center area.

4. Every effort will be made to make the day in the area correspond to
the square assignment for the day. Should an area prove active in enemy contacts,
a signal may be made to remain in the active area. In this event, one of the
other area assignments may be shipped. If it is desired to move the area in
any direction, this can be done by shifting the center of the square in that
direction.

5. When an assignment is made that does not correspond with the schedule,
a message will be sent giving rendezvous point and the day. (i.c. MD XW JS)
This means rendezvous at position "K" on 23rd.

6. In the event information is received concerning enemy forces, the
Group Commander will give appropriate signal in order to intercept the enemy.
The group should keep concentrated to inflict maxium damage in the shortest time.

7. Submarines will endeavor to be in the center of their respective areas
at sunset of each day. This will facilitate a rendezvous, if it becomes
necessary. Normally, movement from one area to another should be made at night.

8. Once contact is made submarines will operate in accordance with enclosure
(B), "Coordinated Attack Doctrine". During this patrol, change paragraph 203(c)
of the doctrine to read: "Immediately transmit the bearing and distance from
the nearest Group Position Point, the estimated course of the enemy." This doctrine
is primarily designated for use against slow convoys and is not practical to
employ for high speed targets. In the event the wolf pack operates against a
high speed task force, a signal will be issued covering the disposition of the
submarines. In general, submarines will spread out along the expected track of
the task force a sufficient distance apart so that one submarine, after complet-
ing attack, can send target data to the next submarine on the line in time to
permit the latter to gain attack position.

[HANDWRITTEN: (15)]
(2) ENCLOSURE (B)

— page 220 —
C-O-N-F-I-D-E-N-T-I-A-L

8. Submarines will zig-zag enroute to and while in the patrol area.

                                Schedule of Group Positions

Day         Date        Center Position Square

1.          16 April    Enter area mid-point
2.          17 April    V
3.          18 April    B
4.          19 April    D
5.          20 April    E
6.          21 April    E1
7.          22 April    E2
8.          23 April    U
9.          24 April    J
10.         25 April    K
11.         26 April    K
12.         27 April    L
13.         28 April    L
14.         29 April    Q
15.         30 April    Q
16.         1 May       R
17.         2 May       R
18.         3 May       S
19.         4 May       K
20.         5 May       L
21.         6 May       Q
22.         7 May       R
23.         8 May       S
24.         9 May       J
25.         10 May      E2
26.         11 May      E2
27.         12 May      J1
28.         13 May      C1
29.         14 May      A1
30.         15 May      W1
31.         16 May      Depart Area.

                                    - 3 -
                                    c o p y

[HANDWRITTEN: (16)]
[HANDWRITTEN: L]                                                                                             [HANDWRITTEN: L]

— page 221 —
C-O-N-F-I-D-E-N-T-I-A-L

COMMUNICATION PLAN

1. The submarine Coordinated Attack Code shall be used for all
signals - Enclosure (C). A careful study of this code will be made enroute
to area to facilitate its use.

2. All submarines will have their radio sets carefully calibrated
to certain frequencies and a schedule of these frequencies will be found
below. Frequencies will be shifted at 0000 G.C.T. An alternate table is
provided, if found necessary to use and will only be changed on signal.
                                                                Primary Alternate
Day                                                             Freq.    Freq.

April 3    7  11  15  19  23  27 May 1   5   9  13  17         2006     265
      4    8  12  16  20  24  28    2   6  10  14  18         2102     304
      5    9  13  17  21  25  29    3   7  11  15  19         2160     402
      6   10  14  18  22  26  30    4   8  12  16             2204     450

3. Ships submerged will transmit essential information (When
possible) on the vertical antenna using the correct frequency for the day.

4. While submerged, submarines will endeavor to listen in for first
five minutes of each hour on this frequency.

5. Tactical messages and contact reports will be receipted for.
Submarines use two-lettered coded CW prior contact and plain language voice
after first attack has been completed.

6. Emergency signals such as: "Aircraft sighted. Im diving", etc.
should be coded and readily available in the radio room for immediate trans-
mission.

                                                G. E. PETERSON
                                                Captain, U.S.N.

- 4 -
c o p y

ENCLOSURE (B)

[HANDWRITTEN: (17)]

— page 222 —
[HANDWRITTEN: Captain Haislip,
This is excellent.
F.J. Lowry]
FF12-10/A16-3(15)[HANDWRITTEN: (16)] SUBMARINE FORCE, PACIFIC FLEET
Serial 01234
CONFIDENTIAL
FIRST ENDORSEMENT to
CTG 17.15 Report of
Coordinated Attack Group.

From:
To :
Via :

Subject:

1.
ate in Task Force Seventeen. The group conducted its patrols in the
China Sea Area south of Formosa.

2.
enemy ships and the other of eight; each convoy was heavily escorted.
Both convoys were aggressively attacked by all the submarines in the
attack group, and seven ships in the first convoy were sunk or damaged
while six ships and one destroyer escort were sunk in the second con-
voy, and the remaining two other ships were probably sunk. In each
case, an early contact made by one of the submarines enabled the other
two to get in on the convoy hours later. In the first case, the U.S.S.
BANG (SS385) made contact and succeeded in making four night attacks,
sinking one and damaging two others. She then became a trailer for
the remainder of the convoy while the U.S.S. PARCHE (SS384) and U.S.S.
TINOSA (SS283) conducted attacks that resulted in the sinking of two
more vessels and the damaging of two others. In the second convoy at-
tack, the TINOSA made the initial contact and by his report all three
were able to make a series of running attacks at night which practi-
cally eliminated the convoy.

3.
are noted. The size of a coordinated attack group should be closely
related to the expected average size of convoys in use by the enemy
and the strength of escorts provided. The primary mission of an at-
tack group is to eliminate any convoys encountered. The attack group
was of sufficient size to do exactly this in the case of the second
convoy contacted. In the case of the first convoy attack, the convoy
was attacked by all three submarines more or less simultaneously
but resulting damage was obtained by one submarine making a series of
night attacks upon three of the ships while the other two made two
separate day time attacks upon four more.

4.
first, wide dispersion for efficient reconnaissance cover; and second,
quick concentration in order to conduct an effective attack. These
two naturally conflict one with the other and a happy medium must be
achieved. If the number of submarines in an attack group is too
[HANDWRITTEN: (2)]
[HANDWRITTEN: 7 0295 F4253 R]
mr
Care of Fleet Post Office,
San Francisco, California.
17 June 1944
NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.

The Commander Submarine Force, Pacific Fleet.
The Commander-in-Chief, United States Fleet.
The Commander-in-Chief, U. S. Pacific Fleet.
War Patrol of Coordinated Attack Group 17.15 from
29 March to 23 May 1944.

This was the fourth coordinated attack group to oper-
The group conducted its patrols in the

The group contacted two convoys, one consisting of 12
each convoy was heavily escorted.
by all the submarines in the
first convoy were sunk or damaged
escort were sunk in the second con-
ships were probably sunk. In each
submarines enabled the other
In the first case, the U.S.S.
making four night attacks,
then became a trailer for
PARCHE (SS384) and U.S.S.
resulted in the sinking of two
In the second convoy at-
contact and by his report all three
attacks at night which practi-

The comments in paragraph 4 of basic correspondence
attack group should be closely
size of convoys in use by the enemy
provided. The primary mission of an at-
convoys encountered. The attack group
this in the case of the second
the first convoy attack, the convoy
submarines more or less simultaneously
by one submarine making a series of
ships while the other two made two
upon four more.

Attack groups are confronted with two problems; i.e.,
for efficient reconnaissance cover; and second,
in order to conduct an effective attack. These
one with the other and a happy medium must be
the number of submarines in an attack group is too

- 1 -

— page 223 —
FF12-10/A16-3(15)/(16)
Serial 01234

CONFIDENTIAL

FIRST ENDORSEMENT TO
CTG 17.15 Report of
Coordinated Attack Group.

Subject: War Patrol of Coordinated Attack Group 17.15 from
           29 March to 23 May 1944:

— page 224 —
[STAMP: SECRET] (crossed out)
[STAMP: DECLASSIFIED]
SS283/S68
Serial: 001

[STAMP: DECLASSIFIED]

[STAMP: SECRET] (crossed out)
U.S.S. TINOSA (SS-283)
c/o Fleet Post Office,
San Francisco, California,
29 January, 1945.

From: The Commanding Officer.
To : The Commander Submarine Force, PACIFIC FLEET.
Via : Official Channels.

Subject: Fox Mike Sonar Tests. [STAMP: RECEIVED S-C FILES]
[STAMP: 30 FEB 1945]
Reference: (a) Commander W. D. IRVIN'S memorandum, and [HANDWRITTEN: ROUTE TO (8)]
instruction. [HANDWRITTEN: Op File No. SS283]
[HANDWRITTEN: Use No. ]
Enclosure: (A) Number one track chart. [HANDWRITTEN: Copy No. ]
(B) Number two track chart.
(C) Number three track chart. [HANDWRITTEN: L H S R]

1. If possible and feasible, TINOSA was to conduct the
following tests with FM Sonar:

(a) Actual test of equipment to determine whether
it could locate Japanese mines(area North of
FORMOSA suggested).
(b) Use against single patrol vessels to determine
whether Japanese can detect FM in operation.
(c) If (b) was successful, use FM to facilitate
evasion during depth charge attack.

2. This report is made up with paragraphs to cover FM
operation in chronological order as it was used. No attempt at
general analysis of FM will be made until the conclusion of the
report.
The Commanding Officer's remarks and thoughts during tests are
recorded only in the interests of presenting a complete picture.

3. Refer to Track Chart #1.

The restricted area between MIYAKO JIMA and OKINAWA
JIMA is believed mined. However, this restricted area is laid
out
to show a possible passage from each of NANSEI SHOTO close around
the south and west tip of OKINAWA JIMA to NAHA, without passing
through the restricted zone. This possible passage is mineable,
but is not shown as mined. Therefore I decided on a submerged
patrol of one day to cover this possible route.

Submerged at 0627(I) on 22 December, 1944. Commenced
closing OKINAWA JIMA. No traffic of any sort sighted. 1237(I)
Manned
No traffic so decided to test FM sonar in mineable water.
FM and commenced closing 100 fathom curve. Keeping accurate log of
position but having trouble going exactly where I wish because of
[STAMP: COPY]
- 1 - [STAMP: CONF]
[STAMP: OPNAV HIST]
[HANDWRITTEN: BY 9/3/1C DATE 5-9-63]

— page 225 —
SS283/S88
TOP SECRET
U.S.S. TINOSA (SS283)
hf
TOP SECRET

Subject: Fox Mike Sonar Tests (Cont'd)
and

— page 226 —
SS283/S68
[STAMP: TOP SECRET]
Subject: U.S.S. TINOSA (SS283) Sonar Tests (Cont'd)

hf
TOP SECRET

(h) that make sense with shallower water available? May-
be the current slides them off the shelf, same as
our drill mines at Pearl. Maybe our position was out
500 yards. Was just too busy to use fathometer and QC
echo ranging gear for checking. Those mines sounded
real.

(i) Would it be wise to call attention to our presence
by using QC? How about a controlled field?

The following facts are presented:

(1) Operators on FM, Captain, Exec, and BRADY, F.G.,
RT3c, USNR(FM trained).

(2) Sea: Condition 5. Temperature 76°
Direction: From 080° T.

(3) Weather - overcast.

(4) Dept of water 50-200 fathoms.

(5) Bottom - rocky and coral.

(6) Background - rapid shoaling to 30 fathoms.

(7) Current: 1200-1300(I): 000°T, 0.70 kts.
1300-1400(I): 010°T, 0.75 kts.
1400-1500(I): 025°T, 0.75 kts.
1500-1600(I): 035°T, 0.80 kts.
1600-1700(I): 035°T, 0.90 kts.
1700-1800(I): 030°T, 0.75 kts.

(8) BT card - isothermal.

(9) Best range 1400 yards,
bearing 010° relative.

(10) Suspected mine locations:

Contact #1:Lat. 26°00'48" N, Long. 127°36'23"E.
Contact #2:Lat. 25°59'47" N, Long. 127°36'41"E.
Contact #3:Lat. 25°59'43" N, Long. 127°35'59"E.
Contact #4:Lat. 25°59'53" N, Long. 127°37'35"E.

[STAMP: COPY]
On 24 December, 1944, used FM to try and attract two
Japanese sampans and one radio equipped trawler or sampan.
varied from 10,000 yards to 4,000 yards. Unable to get closer, al-
though came to normal approach course. This is completely inconclu-
sive because do not believe sampans were equipped with sound gear.
-3-

— page 228 —
SS283/S68
U.S.S. TINOSA(SS283)
[STAMP: TOP SECRET]
[STAMP: TOP SECRET]
Subject: Mike Sonar Tests (Cont'd)

— page 229 —
[STAMP: DECLASSIFIED]
TOP SECRET
[HANDWRITTEN: qwp] [HANDWRITTEN: 2]
TOP SECRET

SS283/A16/S68
U. S. S. TINOSA (SS 283)
Serial: (0001)
Care of Fleet Post Office,
San Francisco, California,
7 APRIL, 1945.

From: The Commanding Officer.
To : The Commander Submarine Force, PACIFIC FLEET.
Via : Official Channels.
Subject: Report of special Fox Mike Sonar mission con-
ducted during TINOSA War Patrol Number NINE.
Enclosure: (A) Log of Events and Fox Mike Trouble Report.
(B) Track Chart (To ComSubPac only).

1. Enclosures (A) and (B) comprising a true report
of the subject special mission are forwarded herewith.

[SIGNATURE: R.C. Latham]
R.C. LATHAM.

[HANDWRITTEN (vertical, right margin): Com Sub Pac BOX # T5-548 RS # 794]
[HANDWRITTEN (vertical, right margin): FILE S68 JACKET # 1010]

[STAMP: CONFIDENTIAL - OPNAV INST 5500.3]
[HANDWRITTEN: BY H. K. DATE 40260]

— page 230 —
TOP SECRET
SS283/A16/S68
Serial:(0001)

Subject: Log of Events in Connection with Special Mission
Performed by U.S.S. TINOSA (SS283), during NINTH
War Patrol.

— page 231 —
A
The following is a transcription of the provided image, distinguishing between typed text and preserving formatting:

TOP SECRET
SS283/A16/S68
Serial: (0001)

U.S.S. TINOSA (SS283)

TOP SECRET

Subject: Log of Events in Connection with Special Mission
Performed by U.S.S. TINOSA (SS283), during NINTH
War Patrol (Cont'D).

— page 233 —
TOP SECRET
U.S.S. TINOSA (SS283)
TOP SECRET
SS283/A16/S68
Serial:(0001)
7 APRIL, 1945.

Subject: Log of Events in Connection with Special Mission
Performed by U.S.S. TINOSA (SS283), during NINTH
War Patrol (CONT'D)

Data on above contacts are tabulated below:

Contact No. | LAT.N.   | LONG.E.   | DEPTH OF WATER
|||
1.          | 28-21.0  | 129-09.0  | 180 fathom.
2.          | 28-20.8  | 129-08.9  | 180 fathom.
3.          | 28-20.5  | 129-08.7  | 180 fathom.
4.          | 28-21.9  | 129-09.1  | 300 fathom.
5.          | 28-23.4  | 129-09.2  | 450 fathom.

[HANDWRITTEN: 4.]
[HANDWRITTEN: ENCLOSURE "A"]

— page 235 —
[STAMP: DECLASSIFIED]
[HANDWRITTEN: 3]
[STAMP: CONFIDENTIAL]
[HANDWRITTEN: BY H.K. DATE 4 Oct '60]
[STAMP: TOP SECRET]

SS283/S68
Serial: (0002)

U. S. S. TINOSA (SS-283)

Care of Fleet Post Office,
San Francisco, California,
16 MAY, 1945.

From: The Commanding Officer.
To : The Commander Submarine Force, PACIFIC FLEET.

Subject: Fox Mike Sonar Operations during TENTH War Patrol
of U.S.S. TINOSA (SS283)

1. No track chart of FM Sonar operations is submitted
because the results described herein are of interest in an aca-
demic way and exact positions and locations are not of vital
importance in connection with the results obtained.

2. A brief material history follows. The first FM system
installed on TINOSA gave erratic results, but several verified
ranges in excess of 800 yards were obtained on dummy mines during
training. During the EIGHTH War Patrol of TINOSA a contact was
obtained on a suspected Japanese mine at a range of 1400 yards.
During the refit between the EIGHTH and NINTH War Patrol, the FM
projector was replaced because of the appearance of dents in the
original head. After this occurrence, the maximum range obtained
in training, and on the NINTH War Patrol was 300 yards. During
training for the TENTH War Patrol, 300 yards was again the maxi-
mum range obtained. Since the circuit had been checked, tuned,
and rechecked innumerable times, a new projector was installed
as a desperation measure. TINOSA immediately obtained definite
contacts on dummy mines at a range of 1800 yards.

3. On 1 May, 1945, during TENTH War Patrol, TINOSA
closely approached NORTH PASS, TRUK ATOLL. The amber screen and
yard scale dial was removed from the Fox Mike PPI scope in the
conning tower, to provide more light for photography. The west
side of the reef at NORTH PASS was detected on the FM at 1800
yards and was tracked in to 1400 yards. A clear periscope
pass was present on the PPI scope. Simultaneous photo-
graphs were taken of the PPI scope and of PIS ISLAND. The
periscope. The ship was swung left with full rudder and the reef
and pass were tracked astern until they were lost at about 1800
yards on the FM.

4. On 10 May, 1945, in position Lat. 08-27.4N., Long.
151-50.3E, FM sonar detected an object bearing 000° relative,
range 250 feet. Evasive maneuvers consisted in a radical course
change and using negative tank to rapidly change depth from 60
feet to 150 feet. Depth of water by sounding was 525 fathoms, sea
conditions one, water temperature 87°F. At 150 feet contacts were
so numerous on the 400 foot scale that evasion was impossible.

-1-

— page 236 —
TOP SECRET
SS283/S68.
U.S.S. TINOSA (SS283)
TOP SECRET

Subject: Fox Mike Sonar Operations during TENTH War Patrol
of U.S.S. TINOSA (SS283) (CONT'D)

— page 237 —
[STAMP: DECLASSIFIED]
U.S.S. TINOSA (SS-283)

Care of Fleet Post Office,
San Francisco, California,
4 JULY, 1945.

[STAMP: CONFIDENTIAL - OPNAV INBT 5500.30]
[HANDWRITTEN: BY 14 Kie 4 Oct 60]

SS283/S68/(L)

Serial: (0003)

[STAMP: DECLASSIFIED]
[STAMP: TOP SECRET]

From: The Commanding Officer.
To : The Commander Submarine Force, PACIFIC FLEET.

Subject: Fox Mike Sonar Operations during ELEVENTH War Patrol
of U.S.S. TINOSA (SS283).

Enclosure: (A) Track Chart No. 1 - TSUSHIMA STRAITS.
(B) Track Chart No. 2 - LA PEROUSE STRAITS.
(C) Table of FM Sonar Contacts.
(D) Extracts from NARRATIVE.

1. The following narrative covers the Fox Mike Sonar
Operations of U.S.S. TINOSA, during the ELEVENTH War Patrol
of U.S.S. TINOSA. Fox Mike Sonar tracked false target shell to 750
yards prior to TSUSHIMA passage.

2. NARRATIVE (All times ITEM, -9)

6 JUNE, 1945
0244 At rendezvous with U.S.S. BOWFIN and U.S.S. FLYING FISH. Lat.
34-03.0N. Long. 128-47.5E.
0253 Manned FM sonar, on surface. Sea condition 1-2.
0255-
0340 Data during this period is missing. Contacts were obtained
immediately on manning the FM sonar. Most of these were ev-
aluated as fish, but three probable mine contacts were noted.
All contacts were on the 300 foot scale with probable mines
appearing at 275 feet, as follows:

Contact No. | Time | Lat N | Long E
1 | 0257 | 34°-04.4' | 128°-47.2'
2 | 0258 | 34°-04.8' | 128°-47.4'
3 | 0258-30 | 34°-04.8' | 128°-47.1'

0414 Entered area. Submerged at TINOSA'S initial point Lat.34-11.5N
Long. 128-51.5E. Making run at 130 feet keel depth, 4 degree
rise bubble. Depth of 130 feet was chosen to allow a little
clearance between periscope sheers and possible mines laid at
75 feet, without deviating too far from the optimum depth of
100 feet, for this mount.
Soundings were taken on the NGA fathometer everyfive minutes
and plotted. A current of 1 knot setting along the track was
assumed. No periscope observations were made. From soundings,
two possible positions were indicated. One position included
a one knot current and showed us slightly east of our intend-
ed track. The second position, which later proved correct,

- 1 -
[STAMP: COPY]

— page 238 —
T P SECRET
SS283/S68(L)
Serial: (0003)

[HANDWRITTEN: hf]
4 JULY, 1945.

Subject: Fox Mike Sonar Operations during ELEVENTH War
         Patrol of U.S.S. TINOSA (SS283)

— page 239 —
[STAMP: TOP SECRET]
SS283/S68/(L)
Serial: (0003)

4 JULY, 1945.

Subject: Fox Mike Sonar Operations during ELEVENTH War
         Patrol of U.S.S. TINOSA (SS283).

1406 Four more FM contacts evaluated as mines, all contacted at 250
     yards. Plotted in straight line bearing 130-310 true, spacing
     200 feet.

     Number        LAT N..         LONG E.
     1             34-34.7N        129-02.2E
     2             34-34.6N        129-02.3E
     3             34-34.5N        129-02.4E
     4             34-34.4N        129-02.5E

1545 FM interference from another submarine.
2100 Surfaced.

     An analysis of all FM contacts indicated the follow-
ing probabilities. The contacts at 0253 are in all probability part
of the mine fields contacted previously by SEA HORSE and CREVALLE.
These are estimated, because of lack of pattern and order, to be part
of an anti-submarine field, perhaps laid in 1941, and since scram-
bled up by storms and time.

     The contacts at 1114, 1349, 1353 and 1406 are ev-
aluated as mine lines laid fairly recently. These four lines showed
a regular spacing and line of bearing. The first line at 1114 was
on line of bearing 110-290 with spacing at 150 feet. The fact that
TINOSA apparently scraped a mine cable of this group doubly veri-
fies its existence. The second, third, and fourth mine lines were
on lines of bearing 130-310 with spacing 200 feet. The third line
was distant 750 yards bearing 048 from the second, and the fourth
line was distant 1150 yards bearing 048 from the third.

     The ranges at which lines two, three, and four were
contacted may possibly indicate depth settings of 10 feet, 75 feet,
and 45 feet, respectively. Admittedly the ranges at which contact
was lost would be a better indication, but unfortunately this data
was not obtained.

     The passage of LA PEROUSSE STRAIT was made on the
surface at 18 knots on the night of 24-25 JUNE, 1945. FM Sonar was
not used and no mine contacts were made.

     A large Russian freighter, on westerly course, was
seen leaving the westerly entrance of LA PEROUSSE just prior to our
passage. This, coupled with our own clear passage on the surface,
would seem to indicate that mines in this strait are laid as an
anti-submarine measure only.

                                             /s/ R. C. LATHAM.

[STAMP: COPY]

— page 242 —
[STAMP: TOP SECRET]
SS293/S69/(L)
Serial: (0003)

T O P S E C R E T

NARRATIVE:

6 June 1945.
0244 At rendezvous with U.S.S. BOWFIN and U.S.S. FLYING FISH. Went
 close aboard FLYING FISH and exchanged pleasantries by megaphone.
0414 Entered area. Submerged.
1116 After engineroom, maneuvering, and after torpedo room reported
 as if a cable had scraped down the port side.
1200 Position. Lat. 34-30N., Long. 128-57E.
2100 Surfaced in condition 5 sea. Obtained first fix since diving.
 The expected northeasterly set did not occur and we are 20
 miles behind estimated position. Soundings had indicated this
 possibility.
 MITSU SHIMA light on TSUSHIMA bearing 123°(T), distance 7 miles
 MAKINO SHIMA light at FU SAN appeared as dimmed, steady white.

2118- S/C#5 & 6. Practically drowned the bridge watch as we worked
2230 west and north on four engines, around these southeast bound
 ships which are probably enroute from FUSAN to SHIMONOSEKI.

24 June 1945.
 During the night rendezvoused with FLYING FISH, BOWFIN and
 SPADEFISH as per schedule.
0300 Submerged, in company.
0905 Surfaced to remove rag from #2 Sanitary Tank Discharge Stop
 Valve. Tank has flooded and is spewing evil contents into ship
 through a leaky flapper valve in crew's head. Not nice for 17
 hour dive. Visibility 1000 yards.
0925 Submerged. Trouble remedied.
1200 Position. Lat. 46-12N., Long 140-02E.
2001 Surfaced. Rendezvoused and commenced passage through LA PEROUSSE
 STRAIT, in column: U.S.S. FLYING FISH, U.S.S. TINOSA, USS
 BOWFIN, and U.S.S. SPADEFISH.
2251 S/C #22. Sighted lights and detoured to south to avoid properly
 illuminated Russian ship on westerly course.
2325 The Russian turned on a searchlight and briefly swung it over
 our column, then turned it off again. Range about 7000 yards.
 Visibility fair in light haze.

25 June 1945.
0100 S/C #23. SJ contact on small ship believed to be a patrol.
 Not sighted. We passed at a least range of 4900 yards, and
 apparently did not alert him.
0200 Visibility about 1000 yards. Subs in column, speed 18 knots,
 distance between ships about an even 1100 yards.
0335 Proceeding independently.
0400 Visibility good. Several subs in sight at various times.
1200 Position. Lat. 45-54N., Long 146-08E.
2344 S/C#24. Exchanged recognition and information with U.S.S. DACE
 by means of SJ radar.
ENCLOSURE (D)
[STAMP: COPY]

U.S.S. TINOSA (SS293)

4 July 1945

— page 243 —
END OF REEL [HANDWRITTEN: # 1]
JOB NO. [HANDWRITTEN: F-108]
[HANDWRITTEN: AR-46-22-1]
[HANDWRITTEN: TINOSA (SS-283)]

|||| 1.0
|||| 1.1
|||| 1.25

|||| 4.5 |||| 2.8 |||| 2.5
|||| 5.0 |||| 3.2 |||| 2.2
|||| 5.6 |||| 3.6 |||| 2.0
|||| 6.3 |||| 4.0 |||| 1.8
|||| 7.1
|||| 8.0
|||| 1.4 |||| 1.6

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