Double deadrise with multiple reflex chine boat hull structure and engine mounting system

The double deadrise with multiple reflex chine boat hull structure and engine mounting system relate to designs for power boat hull structures and engine mounting systems. The hull structure combines the use of two pairs of bottom surfaces, reflex chines and side panels to form a double deadrise hull structure. This design imparts a highly efficient means for dynamic tracking, thereby, preventing "slide-out". The design also enables the hull structure to quickly and easily achieve a plane. The engine mounting device provides an improved means for securing and supporting an engine to a hull structure. The engine mounting device permits the hull structure to have a high transom, reduces the space in the working compartment that would otherwise be occupied by the engine, engine housing, or engine well, permits the proper positioning of the propeller within the water reservoir to achieve optimum thrust performance, provides static flotation and incorporates all of the benefits achieved in the new hull design. The engine mounting system adds approximately two feet of planning surface to the stern which assists the hull structure to maintain an even keel, better trim, and to quickly and easily climb onto a plane without a pronounced sternward pitch.

DESCRIPTION 
1. Technical Field 
This invention relates to the technical field of designs for power boat 
hull structures and engine mounting systems. 
The structural design of a boat hull is important for static and dynamic 
buoyancy, dynamic tracking, and static floatation. The engine mounting 
system is important to secure the propulsion means to the boat hull 
structure in a manner and position such that optimum efficiency is 
achieved. 
2. Background of the Invention 
The design of a boat's hull structure has significant effect on the boat's 
utility, performance and appearance. To propel the boat forward or 
sternward a propulsion means, such as an engine, must be securely attached 
to the boat's hull structure. The location, weight and thrust of the 
engine significantly affect the design and operation of a high-speed 
planing power boat. Some hull structures are designed to use 
inboard/outboard engines, other designs use outboard engines. 
When an inboard/outboard engine is used, a large amount of water is 
displaced. To maintain stability and an even keel, the inboard/outboard 
engine must be positioned near the hull structure's center of buoyancy. A 
large portion of the interior working and riding compartment is therefore 
occupied by the inboard/outboard engine and engine housing unit. 
When an outboard engine is used, the hull structure must have a secure 
transom positioned fairly close to the water-line. The outboard engine is 
attached to the transom. The effectiveness of the outboard engine is 
dependent upon the propeller's position within the water. An engine well 
must also be provided to accommodate the engine housing and to help 
prevent swamping of the working area when the engine is run in reverse. A 
large portion of the interior working or riding compartment is occupied by 
the engine well. There is also a greater likelihood the interior 
compartment will be swamped because the transom is so low. 
The hull structure's design effects the boat's stability and performance. 
The shape, length, breadth, depth, and displacement of the hull structure 
determine the boat's draft, freeboard, and planning characteristics. A 
variety of designs have been invented. The most popular recreational 
high-speed planning power boat design is the "V"-shaped hull structure. 
Some "V"-shaped hull structures utilize either indented or reflex chines. 
Lantz (U.S. Pat. No. 4,528,931), Charlins (U.S. Pat. No. 4,453,489), Wood 
et al. (U.S. Pat. No. 4,398,483), Wood et al. (U.S. Pat. No. 4,233,920), 
Schoell (U.S. Pat. No. 4,193,370), Wood Jr. (U.S. Pat. No. 4,128,072), 
Nescher (U.S. Pat. No. Des. 244,769), Livingston (U.S. Pat. No. Des. 
236,333), Livingston (U.S. Pat. No. Des. 235,530), Baker (U.S. Pat. No. 
Des. 227,708), Simpkins (U.S. Pat. No. Des. 221,808), Yost (U.S. Pat. No. 
Des. 3,568,617), Dougherty (U.S. Pat. No. Des. 214,765), Ross (U.S. Pat. 
No. 3,303,809), Stamas (U.S. Pat. No. Des. 205,604), Schoell (U.S. Pat. 
No. 3,117,544), Rowland (U.S. Pat. No. Des. 196,211), and Cale (U.S. Pat. 
No. 3,091,206), Tritt (U.S. Pat. No. Des. 190,400) and Carr (U.S. Pat. No. 
2,044,771) are examples of various design disclosures which utilize a 
"V"-shaped hull structure in combination with chines. 
Other hull structure designs use a tunnel-shaped hull. Moyer (U.S. Pat. No. 
4,192,248), Austin (U.S. Pat. No. 3,937,164), Payne (U.S. Pat. No. 
3,709,179), Leger (U.S. Pat. No. Des. 193,041) and Canazzi (U.S. Pat. No. 
Des. 191,807) all incorporate a tunnel-shaped hull design with the use of 
chines. 
Reflex chines can greatly improve the efficiency of a hull structure. Given 
the same general characteristics and power-input, boats with pronounced 
chines could have a lesser wetted hull surface area than do boats without 
chines. By achieving a reduced wetted hull structure, the boat will travel 
faster for a given rate of fuel consumption than will a similar boat not 
having that special feature. Reflex chines also provide the boat with a 
means for better tracking during operation because water is channeled 
along the bottom of the hull parallel to the keel. The location, number, 
and angle of the chines have given rise to the many different patents. 
Similarly, boats with shallower drafts climb more easily onto a plane than 
do boats with a greater draft. A single method or concept for using a 
specific hull structure or chine design has not been generally accepted in 
the sporting boat industry. This illustrates the unobvious nature of using 
differently designed hull structures in combination with differently 
designed chines. 
Boats utilizing a "V"--or tunnel-shaped hull structure design still 
experience considerable negative effects, and the placement of chines onto 
the hull structure only partly overcomes the inadequacies. These boats 
still tend to "slide out" on turns and the wetted hull surface is only 
minimally reduced. In addition, problems such as the engine taking up 
space in the working compartment, the positioning of the outboard motor, 
the use of a low transom, and the swamping of the working compartment 
still plaque the sporting boat industry. This invention, to a very large 
extent, overcomes these problems. 
Another very important factor in the design of boats is the appearance of 
the boat hull structure. Similar to the automotive industry, appearance is 
a major marketing factor. A sleek appearance on a power sport boat 
increases its marketability. Sleekness is perceived by the public to 
indicate a positive performance and ability to achieve high speeds. On 
most boats, the multiple use of chines breaks the contour of the boat 
hull. This reduces the boat's sleekness and streamlined appearance. Even 
though the hull is submerged during operation, the hull is readily in view 
when the boat is on a trailer or in dry dock. 
To the applicant's knowledge, only three prior art disclosures address the 
issues of swamping and removing the need for an interior engine well. 
Sigler (U.S. Pat. No. 2,764,119), Yost (U.S. Pat. No. 2,842,086), and 
Finze (U.S. Pat. No. 4,306,703) disclose different gill bracket apparatus 
designed to support the outboard engine astern of the transom. 
Although the use of a chine is not new, no known prior art illustrates a 
double deadrise hull structure in conjunction with the specific angular 
and locational characteristics of the reflex chines of this invention. 
This hull structure is unique and unobvious. The present invention also 
has an extremely sleek and streamlined appearance, increasing its 
marketability over the prior art. Nor does any prior art teach that the 
bottom of the engine mounting device should conform to the same contour of 
the attached hull structure including the use of chines. The applicant's 
engine mounting device is novel and unobvious. 
OBJECTIVES OF THE INVENTION 
It is the general objective of the present invention to provide a 
high-speed planing power boat hull structure which has low frictional drag 
characteristics, has adequate static and dynamic buoyancy, quickly and 
easily climbs to a plane when propelled forward on water, has a relatively 
small static and operational draft, has a sufficient static and 
operational freeboard, does not unduly pitch sternward when the propeller 
thrusts and accelerates the boat forward, and has dynamic tracking such 
that the structure does not "slide out" on a turn. 
Another objective of the present invention is to design said hull structure 
with sufficient stability to prevent static or operational rolling, to 
achieve high speeds and a high degree of performance when operated, and to 
statically float in the unlikely event the structure were to break apart. 
In the second embodiment, it is the further objective of the present 
invention to provide an engine mounting system which positions an outboard 
engine astern, provides a second and lower transom and engine mount, 
provides a lower and exterior engine well, acts as an added flotation 
chamber to support the weight of the engine, shifts the center of buoyancy 
sternward thus reducing the torque arm caused by the thrust of the 
propeller, removes the need for an interior engine well, enables the use 
of a high first transom, and provides a swimming platform with nonskid 
steps. 
In the third embodiment, it is the further embodiment of the present 
invention to provide an engine mounting system which positions an 
inboard/outboard engine further sternward, acts as an added flotation 
chamber to support the weight of the engine, shifts the center of buoyancy 
sternward thus reducing the torque arm caused by the thrust of the 
propeller, reduces the amount of interior working space occupied by the 
inboard/outboard engine and engine housing unit, and provides a swimming 
platform with nonskid steps. 
DISCLOSURE OF INVENTION 
The present invention overcomes the previously mentioned disadvantages of 
the prior art while achieving the described general and specific 
objectives. The specific features of this invention, the double deadrise 
with reflex chine hull structure and the engine mounting system, are 
particularly suited for high-speed planing power boat hull structures of 
relatively small draft. This invention incorporates a combination of 
apparatus to produce a hull structure with low frictional drag 
characteristics, and reduced wetted hull area when the hull structure is 
propelled through water. The features of this invention imparts great 
stability and performance to the hull structure, giving the hull structure 
a sleek streamlined appearance, and providing low draft, sufficient 
freeboard, and static and operational buoyancy. This invention also 
provides the boat with a highly efficient means for dynamic tracking, for 
preventing "slide-out", and for quickly and easily achieving a plane. 
The invention comprises a new hull design which incorporates a double 
deadrise hull structure with multiple reflex chines. The hull structure 
comprises five main areas: the keel, the stem, the bow hull, the aft hull 
and the transom. The keel and the stem lie within a vertical plane upon 
which all the elements of the hull structure are symmetrically disposed. 
The bow hull is a pair of longitudinal curvilinear planing surfaces which 
intersect the stem at an obtuse angle which imparts a "V"-shape to the bow 
hull when viewed from a transverse position perpendicular to the keel. The 
bow hull and stem have a fairly sharp static angle of entry. The aft hull 
is a pair of longitudinal curvilinear planing surfaces comprising a first 
and second pair of bottom surfaces, reflex chines, and side panels. The 
aft hull merges with the bow hull in a smooth curvilinear manner. The 
transom is a planar surface connecting the sternmost edges of the aft 
hull. The transomhas a slight aft-perpendicular. 
The planes of the first pair of bottom surfaces intersect at the keel. The 
intersection of the projected planes of the second pair of bottom surfaces 
is slightly below the keel at the transom and progressively approaches the 
keel as said planes approach the bow hull. The first angle of deadrise of 
the first pair of bottom surfaces is smaller than the second angle of 
deadrise of the second pair of bottom surfaces. The first and second pair 
of reflex chines angle downward and outward from the respective outer ends 
of the first and second pair of bottoms. The first pair of side panels 
angle upward and slightly outward from the outer ends of the first pair of 
reflex chines. The second pair of bottom surfaces angle upward and outward 
from the outer ends of the first pair of side panels. The width portion of 
each side of the first pair of bottom surfaces is approximately twice the 
width portion of each side of the second pair of bottom surfaces. The 
second pair of side panels angle upward and outward from the outer ends of 
the second pair of reflex chines. The first pair of reflex chines and side 
panels gradually decreases in width and depth as they merge into the bow 
hull slightly forward of the fore end of the keel. The second pair of 
reflex chines and side panels gradually decrease in width and depth as 
they merge together at the bow hull and stem. 
The resistant forces of the water reservoir provide the upward lift forces 
enabling the hull structure to plane. When the hull structure is propelled 
forward the reflex chines and double deadrise bottom surfaces act together 
to harness the resistant forces and force the hull structure to plane on 
the surface of the water reservoir. The result of the lifting action is 
the redution of the wetted hull surface, thereby enabling the hull 
structure to achieve higher speeds without an increase in the rate of fuel 
consumption or necessity for increased power output. 
Once the hull structure has begun to plane on the water surface and is 
being propelled forward, effectively only the first pair of bottom 
surfaces and the first pair of reflex chines contact the water reservoir 
surface. The hull structure rides upon the water contained between the 
first pair of reflex chines, beneath the first pair of bottom surfaces. 
The second pair of bottom surfaces and second pair of reflex chines only 
contain the spray occasioned by the first pair of bottom surfaces and 
reflex chines. The second pair of side panels are completely above the 
operational water line. 
Due to the design of the double deadrise bottom surfaces and the multiple 
reflex chines, the hull structure has greater stability than a 
conventional "V"-shaped hull and acts very similar to a boat with a 
tunnel-shaped hull. The stern, however, does not "slide out" on turns. The 
aft and bow hulls dig into the water reservoir as the hull structure 
rounds a corner rather than sliding over the resisting water. This digging 
effect is due to the changed thrust direction of the propeller and the 
angling of the aft and bow hull planing surfaces. In particular, the 
reflex chines, bottom surfaces and side panels dig into the water 
reservoir rather than skimming or sliding along the water reservoir's 
surface. The angling and positioning of the reflex chines, bottom surfaces 
and side panels increase the static and operational stability of the hull 
structure. These features also give the hull structure an efficient means 
for tracking because water is channeled below the hull structure from fore 
and aft. The reflex chines, side panels and bottom surfaces all act as 
fixed rudders restricting sideward movement. 
The engine mounting device of this invention gives the boat a means whereby 
the engine may be attached thereto, permits the hull structure to maintain 
a high transom and reduces the sacrificed space within the working 
compartment. The engine mounting device permits the proper positioning of 
the propeller within the water reservoir thereby obtaining optimum 
performance of the engine. The engine mounting device also assists the 
hull structure to maintain an even keel, better trim, and to quickly and 
easily climb onto a plane without a pronounced sternward pitch. The engine 
mounting device adds approximately two feet of planing surface to the 
stern of the boat. This provides the hull structure with added lift when 
climbing to a plane. The engine mounting device also provides a means for 
static flotation in the unlikely event the boat were to break apart. In 
addition, the engine mounting device incorporates all of the benefits 
achieved with the new hull structure design. The engine mounting device 
may be attached to a boat having the hull structure of this invention such 
that the bottom portions of the device conform to the same bottom and 
chine contours of the boat hull structure. The engine mounting device may 
also be attached to the transom of any standard hull structure. If this is 
done, the lowest portions of the device meet the bottom of the standard 
hull structure. The device may also be redesigned to generally conform to 
the same bottom and chine contour of any given boat hull structure. 
In the second, third, and fourth embodiments, the configuration of the hull 
structure extends past the transom and continues along the bottom of the 
engine mounting device to terminate at a second transom attached to the 
stern of said mounting device. The engine mounting device is attached to 
the boat transom to give the boat added buoyancy and to support the 
engine. This enables the hull structure to retain a high transom and 
thereby prevent swamping of the working compartment when the boat is 
operated in reverse. An additional and important benefit is the area in 
the working compartment, that would otherwise be occupied by the engine 
housing or engine well, is freed for use by the occupants. Because of the 
increased stern buoyancy, the boat has greater stability both statically 
and operationally. The engine mounting system prevents the hull structure 
from unduly pitching sternward when the boat accelerates because the bow 
is held down when the boat goes on and off a plane. This occurs because 
the center of buoyancy is further sternward. The torque arm, resulting 
from the thrust of the propeller, is shorter and has less lifting effect 
on the bow. The hull structure generally experiences an even keel. 
The second embodiment incorporates the hull structure and engine mounting 
device as disclosed herein in conjunction with the use of an outboard 
engine. The third embodiment incorporates the above mentioned hull 
structure and engine mounting device with the use of an inboard/outboard 
engine. The fourth embodiment incorporates the above mentioned hull 
structure and engine mounting device with the use of a inboard/outboard 
jet engine. Inboard/outboard jet engines are often called inboard turbine 
egines. When an inboard/outboard jet engine is used, this invention allows 
the hull structure to plane on a very shallow water reservoir, even only 
inches of water, without contacting the bottom of the reservoir. This is 
due to the very low operational draft of the hull structure and the 
absence of an extended propeller.

BEST MODE OF CARRYING OUT THE INVENTION 
Referring to the drawings, wherein like numerals indicate like parts, FIGS. 
1-8 illustrate the boat hull structure 1 constructed in accordance with 
the present invention. The invention is a high-speed planing power boat 
hull structure 1 which has a relatively small static draft 2 and very 
small operational draft 3. The hull structure 1 was designed to utilize 
low frictional drag features to enable it to achieve high speeds and yet 
maintain optimal stability and performance. 
The hull structure 1 comprises five main areas: the keel 4, the stem 5, the 
bow hull 6, the aft hull 7 and the transom 8. The keel 4 is horizontally 
positioned within a vertical plane 9 extending from the stern 10 to ahead 
of amidship 11. The keel 4 defines the longitudinal axis 28. The stem 5, 
extends from the fore end of the keel 4, curves forward and upward within 
the vertical plane 9, and ends at the head 12. The aft hull 7 comprises a 
pair of longitudinally extending curvilinear planing surfaces 
symmetrically disposed about the vertical plane 9 and the keel 4, one 
planing surface positioned to the port and the other planing surface 
positioned to the starboard. The bow hull 6 comprises a pair of 
longitudinal curvilinear planing surfaces, one planing surface to the port 
and the other planing surface to the starboard, symmetrically disposed 
about the vertical plane 9 and the stem 5. The pair of surfaces forming 
the bow hull 6 intersect the keel 4, stem 5, and head 12 at an obtuse 
angle such that the bow hull 6 has a "V"-shape when viewed from a vertical 
transverse plane perpendicular to the longitudinal axis 28. The aft hull 7 
merges with the bow hull 6 in a streamlined continuous manner. The transom 
8 is positioned at the stern 10 of the hull structure 1, intersects the 
sternward most end of the aft hull 7, and extends downwardly and forwardly 
to intersect the stern 10 end of the keel 4. The bow hull 6, the aft hull 
7 and the transom 8 have a shallow static draft 2, a shallow operational 
draft 3, a sufficient static freeboard 23 and a sufficient operational 
freeboard 24. The aft hull 7 has an aft-perpendicualr 25. The bow hull 6 
has a static ford-perpendicular 26 and an operational ford-perpendicular 
27. The bow hull 6 also has a sharp static entry angle 29. 
The aft hull 7 has six subpart surfaces: a first pair of bottom surfaces 
13, a first pair of reflex chines 14, a first pair of side panels 15, a 
second pair of bottom surfaces 16, a second pair of reflex chines 17 and a 
second pair of side panels 18. The first pair of bottom surfaces 13, 
reflex chines 14, and side panels 15 are symmetrically disposed about the 
vertical plane 9, extend fore and aft intermediate the bow hull 6 and the 
stern 10, and merge into the bow hull 6 at a first streamlined continuous 
transitional area 19. The second pair of bottom surfaces 16, reflex chines 
17 and side panels 18, extend fore and aft intermediate the stem 5 and the 
stern 10, and merge into the bow hull 6 and the stem 5 at a second 
streamlined continuous transitional area 20. The first pair of reflex 
chines 14 and the second pair of reflex chines 17 gradually decrease in 
width and depth upon merging into the bow hull 6. The aft hull 7 and each 
of its six subparts are designed with a slight tumblehome-stern. A 
tumblehome-stern is where the aft hull 7 narrows slightly as the aft hull 
7 approaches the stern 10. 
The planes of the first pair of bottom surfaces 13 intersect at the keel 4. 
The intersection of the projected planes of the second pair of bottom 
surfaces 16 is slightly below the keel 4 at the transom 8 and 
progressively approaches the keel 4 as the second pair of bottom surfaces 
16 approach the bow hull 6. The first angle of deadrise 21 of the first 
pair of bottom surfaces 13 is less than the second angle of deadrise 22 of 
the second pair of bottom surfaces 16. In the preferred embodiment as 
viewed from a transverse section perpendicular to the stern 10 end of the 
keel 4, the second angle of deadrise 22 is approximately 5 to 15 degrees 
greater than the first angle of deadrise 21. 
The first pair of reflex chines 14 connect the corresponding port and 
starboard sides of the first pair of bottom surfaces 13 to the first pair 
of side panels 15. The first pair of reflex chines 14 angle downward and 
outward from the outermost edge of the first pair of bottom surfaces 13. 
The first pair of side panels 15 angle upward and outward away from the 
outer edges of the first pair of reflex chines 14. The second pair of 
bottom surfaces 16 angle upward and outward away from the outer edges of 
the first pair of side panels 15. 
The second pair of reflex chines 17 connect the corresponding port and 
starboard sides of the second pair of bottom surfaces 16 to the second 
pair of side panels 18. The second pair of reflex chines 17 angle downward 
and outward from the outermost edge of the second pair of bottom surfaces 
16. The second pair of side panels 17 angle upward and outward from the 
outermost edges of the second pair of reflex chines 17. 
Once the propelled hull structure 1 exceeds the speed of laminar flow, the 
resistant forces of the water being displaced by the hull structure 1 
exert an upward lift force on the aft hull 7 and the bow hull 6. The 
result of the lifting action is the reduction of the wetted hull surface. 
Since less water is displaced and the wetted hull surface is reduced, the 
frictional surface area decreases and the hull structure 1 is able to 
travel faster without an increase in fuel consumption or power output. The 
first and second pair of reflex chines 14, 17 assist in reducing the 
wetted hull surface while the hull structure 1 climbs to a plane. 
Once a plane is achieved, the first pair of bottom surfaces 13 act with the 
first pair of reflex chines 14 to direct the resistant forces solely 
against the first pair of bottom surfaces 13 and reflex chines 14. Because 
the first angle of deadrise 21 is less than the second angle of deadrise 
22, the displaced water, which is not contained between the first pair of 
reflex chines 14, is directed away from the hull structure 1 so that only 
the spray will contact the second pair of bottom surfaces 16. This 
maintains the reduced wetted hull surface. The second pair of reflex 
chines 17 prevent the overspray from riding up the second pair of side 
panels 18 and spraying the interior working compartment. This invention 
also gives the hull structure 1 an efficient means for tracking. Similar 
to the concept of a tunnel-shaped hull design, the displaced water in the 
present invention is channeled below the first pair of bottom surfaces 13 
from stem 5 to stern 10 between the first pair of reflex chines 14. 
The angling of the first and second pair of reflex chines 14, 17 and the 
angling of the first and second pair of side panels 15, 18 assist the hull 
structure 1 to maintain stability when rounding a curve during operation. 
A common problem with current boat hull structures is that their aft 
portions "slide-out" or drift sideways when they are making a curve at 
high speeds. This problem is greatly reduced with the present invention. 
The aft and bow hulls 7, 6 dig into the water reservoir when the hull 
structure rounds a curve. The digging effect is due to the changed thrust 
direction of the propeller and the angling of the aft and bow hull 7, 6 
planing surfaces. When rounding a curve, the first and second pair of 
reflex chines 14, 17 and bottom surfaces 13, 16, and the first pair of 
side panels 15 not only channel the water beneath the hull structure but 
they also act as rudders to restrict sideward sway. Due to this inventive 
design the hull structure 1 has phenomenally better stability and 
performance than was previously known in the art of sport-boat design. 
FIGS. 5-8 illustrate the boat hull structure 1 as depicted in FIGS. 1-4 in 
combination with the engine mounting device 30. The engine mounting device 
30 is used in the second, third and fourth embodiments. The first 
embodiment does not utilize the engine mounting device 30. The second 
embodiment utilizes the engine mounting device 30 in conjunction with an 
outboard engine. The third embodiment utilizes the engine mounting device 
30 with an inboard/outboard engine. The fourth embodiment utilizes the 
engine mounting device 30 with an inboard/outboard jet engine. The 
differences between the second, third and fourth embodiments are minor. In 
the third and fourth embodiments, the engine well 31 is not used and the 
engine mount hull 32 is adapted to permit the proper positioning of the 
inboard/outboard propeller or jet into the water reservoir. 
The engine mounting device 30 has two main parts: an engine mount hull 32 
and a second transom 33. Similar to the aft hull 7, the engine mount hull 
32 has six subpart surfaces: a third pair of bottom surfaces 34 meeting at 
keelplate 4', a third pair of reflex chines 35, a third pair of side 
panels 36, a fourth pair of bottom surfaces 37, a fourth pair of reflex 
chines 38, and a fourth pair of side panels 39. The third and fourth pair 
of bottom surfaces 34, 37, reflex chines 35, 38, and side panels 36, 39 
are symmetrically disposed about the vertical plane 9, intersect at a 
second keel, extend fore and aft intermediate the transom 8 and the second 
transom 33, and merge into and extend from the transom 8. The third pair 
of bottom surfaces 34, in essence, are a continuation of the first pair of 
bottom surfaces 13 from the aft hull 7 to the second transom 33. The same 
correlation exists between the third and first pair of reflex chines 35, 
14, the third and first pair of side panels 36, 15, the fourth and second 
pair of bottom surfaces 37, 16, and the fourth and second pair of reflex 
chines 38, 17. The mergence of these third and first, and fourth and 
second elements is in a streamlined and continuous manner. The third pair 
of bottom surfaces 34 have a third angle of deadrise 40. The fourth pair 
of bottom surfaces have a fourth angle of deadrise 41. The fourth pair of 
reflex chines 38 are smaller in width and depth than are the second pair 
of reflex chines 17. The fourth pair of side panels 39 extend upwardly, 
and optionally outwardly, from the outer edges of the fourth pair of 
reflex chines 38. The second transom 33 is the sternward most element of 
the engine mounting device 30 and is integrally connected to the aft edges 
of the engine mount hull 32. The engine mount hull 32 has a second 
aft-perpendicular 42, a shallow static and operational draft 2, 3, and a 
sufficient second static and operational freeboard 43, 44. The engine 
mount hull 32 also angles sternward and slightly upward from the transom 8 
to the second transom 33 and has a slight tumblehome-stern. 
The second transom 33 is of sufficient strength to support either an 
outboard engine or an inboard/outboard engine. The second transom 33 has a 
lower second static and operational freeboard 43, 44 than does the transom 
8. The height of the second transom 33 permits the proper positioning of a 
propeller, attached to an outboard engine, within the water reservoir. 
Alternatively, the engine mount hull 32 may be adapted to accommodate an 
inboard/outboard engine or an inboard/outboard jet engine. The upper 
housing 45 of the engine mounting device 30 accommodates an engine well 
31, if an outboard engine is used, and a pair of diving platforms. 
The hull structure 1 is preferably made of relatively light materials, the 
outer surface thereof having low frictional drag characteristics. 
Fiberglass with an outer gel coat is used in the preferred embodiment. The 
engine mounting device 30 may be made of wood and fiberglass and may be 
partially filled with a means for flotation, such as the expanded rigid 
polystyrene plastic material sold under the trademark Styrofoam, to make 
an inherently strong and rigid outboard engine mount or inboard/outboard 
engine support. 
INDUSTRIAL APPLICABILITY 
The industrial applicability of this invention can be readily ascertained 
by reference to the following example of its use. 
As the hull structure sits statically in a water reservoir the angling of 
the first and second pair of bottom surfaces, reflex chines and side 
panels, in addition to the bow hull, all act to contain the water 
immediately beneath the hull structure. Because the water is restrained 
from escaping laterally, the hull structure is prevented from rolling and 
swaying. The longitudinal length of the hull structure prevents the boat 
from yawing and pitching. In a static position, the hull structure is 
extremely stable and acts similar to a tunnel-shaped hull structure. The 
engine mounting device as shown in the second third and fourth embodiments 
acts as an added buoyancy chamber to support the engine and enable the 
boat to maintain an even keel. The hull structure has a low static draft 
and a sufficient static freeboard. 
As the hull structure is propelled forward the engine mounting device of 
the second third and fourth embodiments prevents sternward pitching by 
supporting the aft hull and holding the bow hull down. Consequently, the 
thrust of the propeller directs the hull structure forward rather than 
downward or upward. Once the hull structure exceeds the speed of laminar 
flow, the resistant forces of the water being displaced by the hull 
structure exert an upward lift force on the aft and bow hulls. The double 
deadrise bottom surfaces act together with the multiple reflex chines to 
direct these resistant forces to a smaller bottom planing surface area. 
The result of the lifting action is the reduction of the wetted hull 
surface. Because less water is displaced and the wetted surface is 
reduced, the frictional surface area decreases and the hull structure is 
able to travel faster without an increase in fuel consumption or power 
output. When the engine mounting device of the second, third and fourth 
embodiment is used, the hull structure is able to quickly and easily climb 
to plane along the water surface. 
When the hull structure is planing and is propelled strictly forward, the 
resisting water is contained between the first pair of reflex chines 
beneath the first pair of bottom surfaces. Of the aft hull subparts and 
engine mounting device, only the first and third pair of bottom surfaces 
and reflex chines ride upon the water's surface. The second and fourth 
pair of bottom surfaces and reflex chines contain the spray occasioned by 
the hull structure's propulsion. The second and fourth pair of side panels 
are generally completely above the operational water line. Because the 
first angle of deadrise is less than the second angle of deadrise, the 
displaced water is directed away from the hull without unduly contacting 
the second pair of bottom surfaces. Only the spray contacts the second 
pair of bottom surfaces. The use of a thus angled double deadrise hull 
structure in conjunction with multiple reflex chines significantly reduces 
the wetted hull surface area and allows the hull structure to travel much 
faster with a less powerful and weightier engine than was previously 
possible. These features also give the hull structure an efficient means 
for tracking because water is channeled below the hull structure from fore 
and aft similar to the effect experienced by a tunnel-shaped hull 
structure. 
Even though this invention incorporates many of the beneficial features of 
a tunnel-shaped hull design, this invention does not skim along the water 
surface as it is making a turn. Rather, when rounding a curve the aft and 
bow hulls dig into the water reservoir and do not "slide-out". The reflex 
chines, side panels and bottom surfaces all act as fixed rudders 
restricting sideward movement. This digging effect is due to the changed 
thrust direction of the propeller and the angling of the aft and bow hull 
planing surfaces. Both pairs of reflex chines and bottom planing surfaces, 
in addition to the first pair of side panels, contact and dig into the 
water reservoir as the hull structure makes the turn. The combination of 
these features not only dramatically increases the hull structure's static 
and dynamic stability and power performance but also gives the hull 
structure a sleek and streamlined appearance.