Field of the Invention
[0001] The present invention relates to boats and boat hulls. More particularly, the present
invention relates to wakesurfing boats, and hulls used for wakesurfing boats.
Background of the Invention
[0002] Wakesurfing is a sport that is growing in popularity. A wakesurfer, initially being
towed behind a boat via a tow rope, rises to his feet on a surf board in a body of
water (e.g., an ocean, a sea, a lake, or a river) similar to a waterskier or a wakeboarder.
In order to achieve an ideal wakesurfing ride, the boat should generate in its wake
a wave that mimics as closely as possible, in view of the type of body of water, a
size, a shape, a power, and a duration, of an ocean wave rising, cresting, and breaking
near a beach, enabling the surfer to traverse back and forth on a face of the wake
wave and ride a crest of the wake wave, similar to an ocean surfer.
[0003] Wakesurfers have been attempting to surf in the wakes of traditional cruising boats,
waterskiing boats, and wakeboarding boats. These traditional classes of boats typically
are designed for one or more of speed, seaworthiness, and handling characteristics.
A problem with attempting to wakesurf behind traditional cruising boats, waterskiing
boats, and wakeboarding boats, however, is that such boats fail to generate sufficiently
large, sufficiently well-shaped, and sufficiently long-lasting wake waves to give
a wakesurfer a long satisfying ride.
[0004] As is well known in the field of fluid dynamics, a boat, when passing through a body
of water, creates separate waves that move in the boat's wake. In general, separate
wake waves originate, respectively, from the boat's bow, centerline, quarter, and
stern. Each wake wave generally forms the arms of a V, with the source of the respective
wake wave being at the point of the V (the boat), and transverse curled wave crests
forming offset from the path of the boat. Wake wave height (Wh) is a function of several
factors, including for example a speed of the boat hull in the body of water, resistance
to the boat hull as it moves through the body of water, Froude number, a shape of
the hull, a length of the hull, a length/beam ratio (L/B) of the hull, a speed/length
ratio (SLR) of the hull, an amount of the boat hull in contact with the body of water,
and an amount of water displaced by the boat as it moves through the body of water.
Traditional cruising boats, wakeboarding boats, and waterskiing boats typically are
configured are configured with planning hulls, have an L/B greater than 3.0, have
light displacements, experience minimal water resistance when moving through the water,
and have optimal seaworthiness and handling characteristics.
[0005] Wake wave shape (Ws) can be affected by several factors, including length of the
waterline (LWL), air trapped beneath the hull, water flowing under the hull, and water
flowing past the bulwarks of the hull. For example, air can be trapped beneath the
hull by being admitted below a raised bow of a traditional boat. This air, exiting
at the stern of the hull, creates turbulence in the wake, giving the wake wave an
undesirable muddy appearance. Water flowing under the hull and past the bulwarks of
a traditional boat typically is directed away from the wake, resulting in a wave shape
Ws with an undesirable wave aspect, slope, and/or power.
[0006] A self-propelled wakesurfing boat, and a hull for a wakesurfing boat, is desired
which will generate the largest, best-shaped, and longest-lasting wake waves possible
in view of the boat's size, displacement, and speed.
Summary of the Invention
[0007] In accordance with the invention, a wakesurfing boat, and a hull for a wakesurfing
boat, for wakesurfing in a body of water, substantially obviates one or more of the
problems caused by the limitations and disadvantages of traditional boats.
[0008] A wakesurfing boat operable in a body of water, in accordance with the invention,
includes a hull. The hull includes a bow, a stern, port and starboard bulwarks, a
bottom, a length, a beam, and a first waterline when the hull is at rest. A substantially
central ridge extends a first depth below the hull bottom proximate the bow, extending
along the length at progressively decreasing depths below the bottom to a substantially
planar bottom portion midway between the bow and the stern. Port and starboard ridges
extend second depths beneath the bottom proximate respective port and starboard bulwarks,
defining with the central ridge a generally M-shaped cross section with port and starboard
concave portions opening beneath the bow, the port and starboard ridges extending
along the length at progressively decreasing depths below the bottom to the substantially
planar bottom portion.
[0009] Port and starboard lateral rounded sponsoons extend beneath the respective port and
starboard bulwarks proximate the stem. Preferably each sponsoon is rounded with an
approximately 150 mm fillet.
[0010] A trim wedge extends from the hull below the stern, and extends forward, defining
two generally triangular faces, toward the substantially planar portion.
[0011] A first rounded stern portion is provided below the stern, immediately aft of, and
attached to, the trim wedge. A second rounded stern portion is defined by the stern
extending from the port sponsoon to the starboard sponsoon.
[0012] A ballast system is supported by the hull, including a plurality of ballast tanks
and a ballast watering system. The ballast tanks are configured and positioned within
the hull to selectively receive ballast water and trim the hull, while the hull is
moving through the water, in one of at least two operating modes, including a nonsurfing,
or cruising, mode, and a dynamic surfing mode. A static surfing mode exists, wherein
the ballast tanks are being flooded, but the hull is not moving through the water,
prior to the dynamic surfing mode
[0013] In the cruising mode, with the ballast tanks substantially empty, the hull has a
first trim angle, bow up, and a second waterline, higher on the bulwarks than the
first waterline. A first amount of displaced water is displaced by the hull. A first
amount of water enters the openings at the bow to the port and starboard concave portions
of the generally M-shaped bottom, and flows under the bottom of the hull. The above
features combine to give the hull a first LWL 1, and subject the hull to a first amount
of water resistance. In the wake of the hull, a first wake wave W1 is generated, having
a first height Wh1, and a first shape Ws1.
[0014] In the dynamic surfing mode, with ballast tanks at least partially filled, or filled
with ballast water, the hull has a second trim angle, stern down, and a third waterline
higher on the bulwarks than the second waterline. A second amount of displaced water
is displaced by the hull, greater than the first amount of displaced water. A second
amount of water, greater than the first amount of water, enters the openings at the
bow of the concave portions of the generally M-shaped bottom, and flows under the
hull. The above features combine to give the hull a second LWL, LWL2, greater than
LWL 1, and further subject the hull to a second amount of water resistance, greater
than the first amount of water resistance. In the wake of the hull, a second wake
wave W2 is generated, having a second wave height Wh2, and a second wave shape Ws2.
[0015] The combination of increased ballast, increased LWL with more of the hull bottom
in contact with the water, increased volume of water passing through the concave portions
of the generally M-shaped bottom, and the resultant increase in water resistance to
the hull results in the hull, in the dynamic surfing mode, generating a wake wave
W2 having a greater height Wh2 than the wake wave W1 generated by the hull in the
cruising mode, and greater in height than wake waves generated by traditional boat
hulls.
[0016] In order to decrease an amount of air under the hull, with its resultant loss of
pressure, which produces the generally muddy-appearing water in the hull's wake, the
deep concave portions have been defined in the hull bottom, and LWL has been increased
to achieve improved performance and an increase in the wetted surface of the hull.
The configuration of the concave portions proximate the bow suppresses a flow of air
under the hull, resulting in a reduced loss of pressure under the hull.
[0017] The combination of water passing around the rounded lateral sponsoons, water passing
beneath the first rounded stern portion, water passing by the second rounded stern
portion, and water passing by the surfaces of the trim wedge, directs water to a convergent
zone in the wake of the moving hull, generating the wake wave W2 with a wave shape
Ws2 having an improved slope and power in comparison to a wake wave shape Ws1 generated
by the hull in the cruising mode, and having a better shape than wake waves generated
by traditional hulls.
[0018] In addition, the wave created by the hull passing, rather than planning, in the water
is due to a reinstatement of atmospheric pressure (1 bar at sea level) following a
disturbance in the water created by passage of the hull therethrough, wherein surface
water is pushed downward, increasing pressure in the water, with atmospheric pressure
following immediately after passage of the hull, which typically creates pressure
fluctuations, resulting in an unsatisfactory wave shape. As discussed above, the combined
hull features of the present invention act together to increase the hull's wetted
surface and its displacement, resulting in a higher water resistance thereto as it
moves through the water in the dynamic surfing mode, generating a larger wake wave,
while the structural hull features at the bow, i.e., the concave portions, both suppress
entry of air beneath the hull, and act as a funnel, carrying water back to where the
trim wedge and the rounded stern features to direct water into a convergent zone in
the wake, to generate the wake wave with a desired shape, in terms of aspect, slope,
and power.
[0019] Additional objects and advantages of the invention will be set forth in part in the
description which follows, and in part will be obvious from the description, or may
be learned by practice of the invention. The objects and advantages of the invention
will be realized and attained by means of the elements and combinations particularly
pointed out in the appended claims.
[0020] It is to be understood that both the foregoing general description and the following
detailed description are exemplary and explanatory only and are not restrictive of
the invention, as claimed.
[0021] The accompanying drawings, which are incorporated in and constitute a part of this
specification, illustrate the presently preferred embodiment of the invention and
together with the description, serve to explain the principles of the invention.
Brief Description of the Drawings
[0022]
Figure 1 is a front perspective view of a wakesurfing boat in accordance with the
present invention;
Figure 2 is a front perspective view of a bottom of a hull in accordance with the
present invention;
Figure 3 is a rear perspective view of the bottom of the hull depicted in Fig. 2;
Figure 4 is a side cross-sectional view of the hull in accordance with the invention,
depicting locations of the ballast tanks;
Figure 5 is a top cross-sectional view of the hull in accordance with the invention,
depicting locations of the ballast tanks;
Figure 6 is a side view of the hull in accordance with the invention, operating in
the cruising mode;
Figure 7 is a side view of the hull in accordance with the invention, operating in
the static surfing mode;
Figure 8 is a side view of the hull in accordance with the invention, operating in
the dynamic surfing mode;
Figure 9 is a side view of the hull, depicting locations of spaced crosssectional
cuts A-M at preselected locations along the length of the hull between the stern and
bow of the hull, respectively;
Figure 10 is a bottom view of the half-hull, as used in naval architectural drawings,
depicting the locations of spaced cross-sectional cuts shown in Figure 9;
Figure 11 is a front cross-sectional view of the hull, in accordance with the invention,
depicting the relative locations of each of the cross-sectional cuts A-M, shown in
Figures 9 and 10;
Figures 12A-12M are cross-sectional views of the hull, in accordance with the invention,
at each of the respective cross-sectional cuts A-M, as shown in Figures 9 and 10;
Figure 13 depicts a trim wedge at the stern of the hull, in accordance with the invention,
and depicts how water flowing under the hull, is directed by the stern wedge into
the hull's wake;
Figure 14 depicts a laterally-rounded sponsoon, in accordance with the invention,
and depicts how water flowing past the rounded sponsoon, is directed by the sponsoon
into the hull's wake;
Figure 15 depicts a first rounded stern portion, in accordance with the invention,
and depicts how water flowing under the hull and past the first rounded portion, is
directed by the first rounded stern portion into the hull's wake;
Figure 16 depicts the generally M-shaped hull, in accordance with the invention, port
and starboard concave portions of the hull in accordance with the invention, and more
particularly how the port and starboard concave portions at the cross-sectional view
depicted proximate Figure 12K and Figure 12L assist in suppressing air flow beneath
the bow and maintaining pressure under the hull, thereby suppressing trapped air under
the hull in accordance with the invention;
Figure 17 depicts water pressure conditions beneath the hull and in the wake of the
hull resulting from the configuration of the hull in accordance with the invention
as depicted in Figures 1-16, and depicts generation of a resultant wake wave having
a desired height, aspect, slope, and power; and
Figure 18 depicts flow of water under the hull having the configuration in accordance
with the invention as depicted in Figures 1-16, wherein the configuration of the bow
acts substantially as a funnel, funneling water aft to where the trim wedge, the laterally-rounded
sponsoons, and the first and second stern rounded portions redirect the water to a
convergent zone in the wake, to shape the wake wave as desired.
Description of the Preferred Embodiment
[0023] Reference will now be made in detail to the present preferred embodiment of the invention,
an example of which is illustrated in the accompanying drawings. Wherever possible,
the same reference numbers will be used throughout the drawings to refer to the same
or like parts.
[0024] In accordance with the invention, as broadly embodied in Fig. 1, a wakesurfing boat
10 includes a hull12. Hull12 includes a bow 14, a stern 16, a port bulwark 17, a starboard
bulwark 18, a center of gravity CG, a first waterline WL 1 defined on the bulwarks
when the boat is at rest in a body of water, a hull bottom 20, a length L, a beam
B, and preferably a length to beam ratio L/B of less than 3.0.
[0025] As broadly embodied in Figs. 2 and 3, hull bottom 20 includes a substantially central
ridge portion 22 extending a first depth d1 below the hull proximate the bow 14. Preferably,
and as shown in Fig.2, the depth of the central ridge portion 22 extends along the
length of the hull bottom 20 at progressively decreasing depths to a substantially
planar portion 23 in the hull bottom 20 midway between the bow 14 and the stern 16.
A port ridge portion 24 and a starboard ridge portion 25 each extend a second depth
d2 below the hull proximate the respective port and starboard bulwarks 17 and 18.
In accordance with the invention, and as best embodied in Figs. 2 and16, the central
ridge portion 22, and the port and starboard ridge portions 24 and 25, combine to
define a substantially M-shaped cross-sectional configuration, with port and starboard
concave portions 26 and 27, defined between the substantially central ridge 22, and
the respective port and starboard ridges 24 and 25. The port concave portion 26 is
open to the body of water at an opening 28 proximate the bow 14, and the starboard
concave portion 27 is open to the body of water at an opening 29, also proximate the
bow 14. Preferably, and as shown in Fig.2, the respective depths of the port and starboard
ridge portions 24 and 25 extend along the length of the hull bottom 20 at progressively
decreasing depths below the hull bottom to the substantially planar portion 23.
[0026] In accordance with the invention, and as broadly embodied in Figs. 3 and 14 , port
and starboard lateral rounded sponsoons 30 and 32 extend beneath the respective port
and starboard bulwarks 17 and 18 proximate the stern 16. Preferably, each sponsoon
is rounded with a lateral fillet 33 and 34 respectively. Each fillet preferably has
a radius of approximately 150 mm. Referring to Fig.1, the port and starboard lateral
sponsoons also are raised higher on the bulwarks 17 and 18, respectively.
[0027] In accordance with the invention, a trim wedge 35 extends below the stern 16 to a
third depth d3. As broadly embodied in Figs. 2 and 3, the trim wedge 35 extends forward
toward the substantially planar portion 23, defining first and second generally triangular
faces 36 and 37.
[0028] In accordance with the invention, and as broadly embodied in Fig.15, the hull further
comprises a first generally rounded stern portion 38 located below the stern 16, immediately
aft of, and attached to, the trim wedge 35. It is further preferred, referring to
Figs.3, 13, and 17, that a second rounded portion 39 be provided at the stern 16,
extending from the port sponsoon 30 to the starboard sponsoon 32.
[0029] In accordance with the invention, a ballast system 40 is supported by the hull 12.
As broadly embodied in Fig. 4 and 5, ballast system 40 includes a plurality of ballast
tanks, including sets of dual tanks, and single tanks 42a, 42b, 43a, 43b 44a, 44b,
45, and 46. Preferably, a ballast watering system including at least one pump (not
shown) is provided to selectively pump ballast water to various selected ballast tanks
in order to trim the hull 12 in various selected trim angles during different operating
modes, as explained in detail below. Preferably, the ballast tanks are configured
with a preselected volume capacity, and positioned on the hull 12, in order to obtain
desired conditions of waterline, LWL, displacement, and trim angle, when the hull
12 is moving through the body of water. For example, dual tanks 44a, 44b are positioned
partly forward of the CG, tank 45 is positioned forward of tanks 44a, 44b. Tank 46,
positioned at the stern, has the largest capacity, greater than approximately 1100
liters of ballast water.
[0030] As a result of the ballasting, it is further preferred that the volumes of the hull
when immersed in salt water, L/B ratios, LWL, and associated hull displacements and
drafts, be established in accordance with the charts below. One of ordinary skill
will recognize that the hull volumes will change when the hull is immersed in fresh
water.
Draft |
Displ. |
L/B |
LWI |
BwI |
Volume |
m |
tonnes |
ratio |
m |
m |
m3 |
0,42 |
15,585 |
2,66 |
12,067 |
4,541 |
15,205 |
0,44 |
16,532 |
2,69 |
12,233 |
4,540 |
16,129 |
0,46 |
17,487 |
2,74 |
12,419 |
4,539 |
17,060 |
0,48 |
18,449 |
2,77 |
12,582 |
4,539 |
17,999 |
0,50 |
19,418 |
2,80 |
12,702 |
4,539 |
18,944 |
0,52 |
20,393 |
2,82 |
12,798 |
4,537 |
19,895 |
0,54 |
21,374 |
2,83 |
12,855 |
4,536 |
20,853 |
0,56 |
22,351 |
2,85 |
12,912 |
4,535 |
21,816 |
0,58 |
23,354 |
2,86 |
12,952 |
4,534 |
22,784 |
0,60 |
24.351 |
2,86 |
12,978 |
4,533 |
23,757 |
0,62 |
25,354 |
2,87 |
13,004 |
4,532 |
24,736 |
0,64 |
26,362 |
2,88 |
13,031 |
4,531 |
25,719 |
0,66 |
27,374 |
2,88 |
13,050 |
4,530 |
26,706 |
0,68 |
28,390 |
2,88 |
13,059 |
4,529 |
27,698 |
0,70 |
29,411 |
2,89 |
13,068 |
4,528 |
28,693 |
0,72 |
30,435 |
2,89 |
13,078 |
4,527 |
29,693 |
0,74 |
31,463 |
2,89 |
|
4,526 |
30,696 |

[0031] Referring to Figs. 9 and 10, the hull 12 is depicted viewed from the side and from
below, respectively, with a plurality of cross-sectional cut lines A-M. Fig. 11 depicts
the hull in cross-section viewed from the bow 14, depicting all of the crosssectional
cut lines A-M. Figs. 12A-12M depict separate cross-sections, viewed from the bow 14,
of each of the cross-sectional cuts A-M. In Figs. 12A-12M, the general flattening
in depth of the central ridge 22, the port and starboard ridges 24 and 25, and the
concave portions 26 and 27 between the bow 14 and the substantially planar hull portion
23. The emergence of the trim wedge 35 also can be seen. More significantly, Figs.
12M, 12L, and 12K depict the configuration of the port and starboard concave portions
26 and 27 at the bow 14 (Fig. 12M) and proximate, but approximately 1.6 m aft of the
bow (Figs. 12K and12L). The position of cross-sectional cuts K and Lis approximately
where the body of water through which the hull moves first touches the hull 12 when
the hull operates in the dynamic surfing mode Mds, described in greater detail below.
The cross-sectional configuration of the concave portions 26 and 27 proximate and
immediately aft of the bow 14 is significant because, as will be explained below,
this configuration reduces pressure loss at the bow 14, thereby suppressing entry
of air, that would otherwise be trapped under the hull12. Suppression of trapped air
under the hull 12 subsequently suppresses turbulent flow of muddy-appearing water
in the wake of the hull 12.
[0032] In accordance with the invention, selective flooding of selected ballast tanks with
selected volumes of ballast water trim the hull in one of three operating modes. As
broadly embodied in Fig.6, hull 12 is depicted operating in a non-surfing, or cruising
mode, Me. As broadly depicted in Fig.?, hull12 is depicted operating in a static surfing
mode, Mss. As broadly depicted in Fig.8, hull 12 is depicted operating in a dynamic
surfing mode, Msd. As embodied in Fig. 6, in the cruising mode, Me, the hull 12 is
moving through the body of water, the ballast tanks are substantially empty, the hull
12 displaces a first amount of displaced water, the hull is trimmed bow up, a second
waterline WL2 is defined on the bulwarks, higher on the bulwarks than the first at-rest
waterline WL 1, a first amount of water enters the openings of the port and starboard
concave portions 26 and 27, and traverses through the length of the concave portions
26 and 27, and the hull 12 encounters a first water resistance Wr1. As a result of
all of the above factors, the hull 12 generates a first wake wave W1 having a first
wave height Wh1, and a first wave shape Ws1. As broadly depicted in Fig. 7, the static
surfing mode, Mss, the hull 12 is not moving through the water, the ballast tanks
are partially filled, the hull displaces an amount of displaced water intermediate
the amounts of displaced water in the cruising mode Me and the dynamic surfing mode
Msd, and the hull12 has a stern down trim intermediate the trims in the cruising mode
Me and the dynamic surfing mode Msd.
[0033] As broadly embodied in Fig.8, in the dynamic surfing mode, Msd, the hull again is
moving through the body of water, the ballast tanks are substantially filled or filled,
the hull12 displaces a second amount of displaced water, greater than the first amount
of displaced water, the hull12 is trimmed stern down, a third waterline WL3 is defined
on the bulwarks, higher on the bulwarks than the second waterline WL2, resulting in
more surface of the hull being in contact with the body of water, a second amount
of water, greater than the first amount of water, enters the openings of the concave
portions 26 and 27 and traverses the lengths of the concave portions 26 and 27, and
the hull 12 encounters a second amount of water resistance Wr2, greater than the first
amount of water resistance Wr1 encountered in the cruising mode Me. In the dynamic
surfing mode Msd, the hull 12 generates a second wake wave W2. As a result of all
of the above factors, a second wave height Wh2 of second wake wave W2 is greater than
the wave height Wh1 of wake wave W1 generated in the cruising mode Me.
[0034] In accordance with the invention, wake wave W2 also has a different wave shape Ws2.
As broadly depicted in Figs. 14 and 18, rounding of the lateral sponsoons 30 and 32
with the approximately 150 mm fillets 33 and 34 deflect portions of lateral flow of
the body of water inward toward the wake of the hull 12. As broadly embodied in Fig.
15, the first stern rounded portion 38 immediately aft of the trim wedge 35 directs
flow of the body of water beneath the hull upward toward the surface in the wake of
the hull 12.The second rounded stern portion 39, assists the lateral rounded sponsoons
to direct water flowing past the bulwarks into the wake of the hull12. Moreover, as
broadly depicted in Fig. 18, water passing below the hull 12 is further directed by
contact with triangular faces 36 and 37 of trim wedge 35 to a center of the wake.
Each of the above factors contributes to water flowing laterally past, and below,
the hull12, being directed to a convergent zone Zc in the wake of the hull12, which
contributes to generation of the wave shape Ws2 with an improved face and crest, having
reduced turbulence.
[0035] Furthermore, the increase in LWL, as a result of the above-described factors in the
dynamic surfing mode Msd achieves improved performance and an increase in the wetted
surface of the hull. As broadly embodied in Fig. 16, the configuration of the concave
portions 26 and 27 proximate the bow 14 maintain higher pressure below the concave
portions, thereby suppressing entry of air under the hull at the bow, subsequently
maintaining desired high pressure areas 50 under the hull, as shown in Fig. 17.
[0036] In addition, as broadly embodied in Fig. 17, the wave created by the hull 12 passing,
rather than planning, in the water is due to a reinstatement of normal atmospheric
pressure 52 (1 bar at sea level) following disturbance in the water created by passage
of the hull therethrough, wherein surface water is pushed downward, increasing pressure
in the water, with atmospheric pressure following immediately after passage of the
hull, which typically creates pressure fluctuations 53 which result in an unsatisfactory
wave shape. The combined hull features discussed above act together to suppress pressure
fluctuations 53 in the water. As broadly embodied in Fig. 18, the structural hull
features, including the concave portions26 ad 27, act as a funnel, carrying water
back to where the trim wedge 35 and the rounded features proximate the stern 16, i.e.
33, 34, and 39, redirect water into the wake to convergent zone Zc, to generate the
wake wave with a desired shape, in terms of aspect, slope, and power.
[0037] The wakesurfing boat further includes a deck, visible in Fig.1, and a pair of counter-rotating
propellers (not shown) to propel the boat.
[0038] One of ordinary skill in the art will understand that the configuration and principle
of operation of the wakesurfing boat and the hull for a wakesurfing boat, in accordance
with the present invention, is not limited to any length of hull. The hull 12 can
have the length L of a yacht, the length L of a cruiser, or the length L of a sport
boat.
[0039] Other embodiments of the invention will be apparent to those skilled in the art from
consideration of the specification and practice of the invention disclosed herein.
It is intended that the specification and examples be considered as exemplary only,
with a true scope and spirit of the invention being indicated by the following claims.
1. A hull for a wakesurfing boat, the hull comprising:
a bow, a stern, a center of gravity CG, a port bulwark, a starboard bulwark, a length
L, a beam B, a first waterline defined on the bulwarks when the hull is at rest in
a body of water, and a bottom extending for a preselected length from the bow to the
stern, the bottom comprising:
a substantially central ridge extending a first depth below the hull proximate the
bow, the substantially central ridge extending along the length at progressively decreasing
depths below the hull to a substantially planar bottom portion midway between the
bow and the stem;
port and starboard ridges extending second depths below the hull proximate the respective
port and starboard bulwarks, defining with the substantially central ridge a generally
M-shaped cross section with port and
starboard concave portions between the substantially central ridge and the port and
starboard ridges, the port and starboard ridges extending at progressively decreasing
depths below the first waterline to the substantially planar bottom portion;
port and starboard lateral sponsoons extending beneath the port and starboard bulwarks
proximate the stern; and
a trim wedge extending below the stern, and extending forward toward the substantially
planar portion; and
a ballast system supported by the hull comprising a plurality of ballast tanks and
a ballast watering system, the ballast tanks configured and positioned in the hull
to selectively receive ballast water to trim the hull, while moving through the water,
in one of at least two operating modes, the at least two operating modes including:
a cruising mode, wherein the ballast tanks are substantially empty, the hull has a
first trim angle and a second waterline, the hull displacing a first amount of water,
and a first amount of water entering openings at the bow of the port and starboard
concave portions of the generally M- shaped bottom, and traversing the length in the
port and starboard concave portions, combining to subject the hull to a first amount
of water resistance; and
a dynamic surfing mode, wherein the ballast tanks are at least partially filled or
filled with ballast water, the hull has a second trim angle and a third waterline,
higher on the bulwarks than the second waterline, the hull displacing a second amount
of displaced water greater than the first amount of displaced water, and a second
amount of water, greater than the first amount of water, entering the openings at
the bow of the port and starboard concave portions of the generally M- shaped bottom,
and traversing the length in the port and
starboard concave portions, combining to subject the hull to a second amount of water
resistance greater than the first amount of water resistance.
2. The hull of claim 1, wherein each of the port and starboard lateral sponsoons has
a rounded lateral edge.
3. The hull of claim 1 or 2, wherein a length to beam ratio (L/B) of the hull is less
than 3.0.
4. The hull according to any of the preceding claims, further comprising a third operating
mode, a static surfing mode, wherein the ballast tanks are partially filled with ballast
water, and the hull has a third trim angle, intermediate the first and second trim
angles.
5. The hull according to any of the preceding claims, wherein when the trim wedge is
configured such that when the hull is moving in the dynamic surfing mode, the trim
wedge interferes with flow of water below the bottom of the hull, directing the water
on port and starboard faces of the wedge to a converging zone in the wake of the hull.
6. The hull according to any of the preceding claims, wherein the ballast watering system
includes at least one pump for adding the ballast water to, and removing the ballast
water from, the ballast tanks.
7. The hull according to any of the preceding claims, further comprising a first generally
rounded stern portion below the stern and aft of the trim wedge.
8. The hull of claim 7, further comprising a second generally rounded stern portion at
the stern extending from the port sponsoon to the starboard sponsoon.
9. The hull according to any of the preceding claims, wherein the ballast tanks comprise
a plurality of sets of single and dual tanks, the sets of dual tanks being positioned
at generally symmetrical locations with respect to one another on the hull, and wherein
at least a portion of a first set of dual tanks is positioned forward of the CG, and
a single tank having a volume greater than the first set of dual tanks, is positioned
proximate the stem.
10. The hull according to any of the preceding claims, wherein when the hull moves through
the body of water in the cruising mode, the hull generates at least one wake wave
having a first height and a first shape.
11. The hull of claim 10, wherein when the hull moves through the body of water in the
dynamic surfing mode, as a result of the increased ballast, the increased amount of
displaced water, the second amount of water passing through the port and starboard
concave portions of the generally M- shaped bottom, the second greater amount of water
resistance to the hull, and the water passing past the sponsoons and the trim wedge,
the hull generates at least one wake wave having a second height that is greater than
the first height, and a second shape.
12. The hull according to any of the preceding claims, wherein the length L is a length
selected from the group consisting of the length of a yacht, the length of a cruiser,
and the length of a sport boat.
13. The hull according to any of the preceding claims, wherein the port and starboard
concave portions are configured to suppress air from entering under the bow.
14. A hull for a wakesurfing boat, the hull comprising:
a bow, a stern, a center of gravity CG, a port bulwark, a starboard bulwark, a length
L, a beam B, a first waterline defined on the bulwarks when the hull is at rest in
a body of water, and a bottom extending for a preselected length from the bow to the
stern, the bottom comprising:
a substantially central ridge extending a first depth below the hull proximate the
bow, the substantially central ridge extending along the length at progressively decreasing
depths below the hull to a substantially planar bottom portion midway between the
bow and the stem;
port and starboard ridges extending second depths below the hull proximate the respective
port and starboard bulwarks, defining with the substantially central ridge a generally
M-shaped cross section with port and
starboard concave portions between the substantially central ridge and the port and
starboard ridges, the port and starboard ridges extending at progressively decreasing
depths below the first waterline to the substantially planar bottom portion;
port and starboard lateral rounded sponsoons extending beneath the port and starboard
bulwarks proximate the stern, each rounded sponsoon comprising a rounded fillet; and
a trim wedge extending below the stern, and extending forward toward the substantially
planar portion;
a first rounded stern portion fixed to the trim wedge aft of the trim wedge; and
a second rounded stern wedge extending between the port sponsoon and the starboard
sponsoon; and
a ballast system supported by the hull comprising a plurality of ballast tanks and
a ballast watering system, the ballast tanks configured and positioned in the hull
to selectively receive ballast water to trim the hull, while moving through the water,
in one of at least two operating modes, the at least two operating modes including:
a cruising mode, wherein the ballast tanks are substantially empty, the hull has a
first trim angle and a second waterline, the hull displacing a first amount of water,
and a first amount of water entering openings at the bow of the port and starboard
concave portions of the generally M- shaped bottom, and traversing the length in the
port and starboard concave portions, combining to subject the hull to a first amount
of water resistance; and
a dynamic surfing mode, wherein the ballast tanks are at least partially filled or
filled with ballast water, the hull has a second trim angle and a third waterline,
higher on the bulwarks than the second waterline, the hull displacing a second amount
of displaced water greater than the first amount of displaced
water, and a second amount of water, greater than the first amount of water, entering
the openings at the bow of the port and starboard concave portions of the generally
M- shaped bottom, and traversing the length in the port and starboard concave portions,
combining to subject the hull to a second amount of water resistance greater than
the first amount of water resistance;
wherein the port and starboard concave portions are configured to suppress air from
entering under the bow; and
wherein the trim wedge, the port and starboard lateral rounded sponsoons, and the
first and second stern rounded portions, are each configured to direct water into
a convergent zone in the wake of the hull.
15. A wakesurfing boat comprising a hull according to any of claims 1 to 14, a deck, and
counter-rotating propellers for propelling the boat.