IV

QUICK REFERENCE

Amver.................................................................................................................................................................................. 

DISTRESS, SEARCH, AND RESCUE

Assistance by SAR Aircraft and Helicopters................................................................................................................... 

Distress and Safety Communications Procedures ........................................................................................................... 

Emergency Position Indicating Radiobeacons (EPIRBs)................................................................................................ 

Frequencies for Distress and Safety ................................................................................................................................ 

Global Maritime Distress and Safety System (GMDSS) ................................................................................................ 

Urgency and Safety Communications Procedures........................................................................................................... 

ELECTRONIC NAVIGATION

LORAN-C........................................................................................................................................................................ 

Satellite Navigation.......................................................................................................................................................... 

EMERGENCY

U.S. Naval Cooperation and Guidance for Shipping (NCAGS)...................................................................................... 

Contamination Prediction System for Merchant Ships at Sea and the MERWARN System .......................................... 

Reports of Hostile Activities............................................................................................................................................ 

Requests for U.S. Navy Assistance in Emergency Situations ......................................................................................... 

NAVIGATIONAL WARNINGS

Coastal and Local, Long Range, and Worldwide Warnings ............................................................................................ 

Ice Information ................................................................................................................................................................ 

NAVTEX.......................................................................................................................................................................... 

Reporting Navigational Safety Information to Shore Establishments............................................................................. 

SPECIAL WARNINGS and Broadcast Stations ............................................................................................................. 

The National Geospatial-Intelligence Agency’s Maritime Safety Information Website..................................................... 
V

THE NATIONAL GEOSPATIAL-INTELLIGENCE AGENCY

MARITIME SAFETY INFORMATION WEBSITE

The National Geospatial-Intelligence Agency (NGA) Maritime Safety Information Website provides worldwide r

query access to extensive menus of maritime safety information 24 hours a day.

Databases made available for access, query and download include Chart Corrections, Publication Corrections, 

Hydrographic Catalog Corrections, Chart and Publication Reference Data (current edition number, dates, title, s

NGA List of Lights, USCG Light Lists, WorldWide Navigational Warning Service (WWNWS) Broadcast War

Maritime Administration (MARAD) Advisories, Department of State Special Warnings, Mobile Offshore Drilling 

(MODUs), Anti-Shipping Activity Messages (ASAMs), World Port Index, and Radio Navigational Aids. Publication

are also made available as PDF files include the U.S. Notice to Mariners, U.S. Chart No. 1, The American Pra

Navigator (Bowditch), International Code of Signals, Radio Navigational Aids, World Port Index, Distances Be

Ports, Sight Reduction Tables for Marine and Air Navigation, and the Radar Navigation and Maneuvering Board Ma

The Maritime Safety Information Website can be accessed via the NGA Homepage (http://www.nga.mil) or dire

http://pollux.nss.nga.mil/. Any questions concerning the Maritime Safety Information Website should be directed to:

MARITIME DIVISION

ATTN: NSS STAFF

ST D-44

NATIONAL GEOSPATIAL-INTELLIGENCE AGENCY

4600 SANGAMORE ROAD

BETHESDA MD 20816-5003

Telephone: (1) 301-227-3296 or DSN 287-3296

Fax: (1) 301-227-4211

E-mail: webmaster_nss@nga.mil
VI

TABLE OF SYMBOLS

LEGEND

Example: A 1 A

(1) (2) (3)

(1) Type of modulation of the main carrier:

A Double sideband

F Frequency modulation

G Phase modulation

H Single sideband (full carrier)

J Single sideband (suppressed carrier)

N Emission of unmodulated carrier

R Single sideband (reduced or variable level carrier)

(2) Nature of signal(s) modulating the main carrier:

0 No modulating signal

1 Single channel containing quantized/digital information without modulating subcarrier, excluding time 

multiplex

2 Single channel containing quantized/digital information with modulating subcarrier, excluding time di

multiplex

3 Single channel containing analog information

9 Multiple channels, separately containing quantized/digital information and analog information

(3) Type of information to be transmitted. “Information” does not include information of a constant, unvarying n

provided by standard frequency emissions, continuous wave and pulse radars, etc.:

A Telegraphy (aural reception)

B Telegraphy (automatic reception)

C Facsimile

D Data transmission, telemetry, telecommand

Note: With 6 kHz, EDW operation in the bands below 30 MHz allocated exclusively for maritime mob

(FC, MO)

E Telephony (including sound broadcasting)

N No information transmitted

W Telegraphy and telephony

AMPLITUDE MODULATION

A1A Continuous wave telegraphy, Morse code

A2A Telegraphy by on/off keying of tone-modulated carrier, Morse code: double sideband

A3E Radiotelephony using amplitude modulation: double sideband

A3C Facsimile

A9W Composite emission of telegraphy and telephony: double sideband

G1D Data transmission

G3E Radiotelephony

H2A Telegraphy by on/off keying of tone-modulated carrier

H2B Selective calling using sequential single frequency code

H3E Radiotelephony: single sideband, full carrier

J3C Facsimile: single sideband, suppressed carrier

J3E Radiotelephony using amplitude modulation: single sideband, suppressed carrier

N0N Unmodulated continuous wave emission

R3E Radiotelephony
VII

FREQUENCY (or PHASE) MODULATION:

F1B Narrow band direct printing (NBDP); Radioteletype

F2A Telegraphy by on/off keying of tone-modulated carrier

F3C Facsimile

F3E Radiotelephony using frequency modulation

Pulse Modulation:

kHz = kilohertz

MHz = megahertz

GHz = gigahertz

TERMS AND ABBREVIATIONS

AOR-E Atlantic Ocean Region-East

AOR-W Atlantic Ocean Region-West

CES Coast Earth Station

DSC Digital Selective Calling

EPIRB Emergency position-indicating radio beacon

GEOLUT Local user terminal in a GEOSAR system

GEOSAR Geostationary satellite system for SAR

HF High Frequency

IOR Indian Ocean Region

LEOLUT Local user terminal in a LEOSAR system

LEOSAR Low Earth Orbit satellite system for SAR

LUT COSPAS-SARSAT Local User Terminal

MCC COSPAS-SARSAT Mission Control Center

MF Medium Frequency

MRCC Maritime Rescue Co-ordination Center

MRSC Maritime Rescue Sub-Center

NBDP Narrow band direct printing

NCS Network Coordinating Station

N.I. No Information

NM Nautical Miles

POR Pacific Ocean Region

RCC Rescue Coordination Center

Rx Receiver

SAR Search and rescue

Tx Transmitter

UTC Coordinated Universal Time