WO2013177155A1 - Hydrofoil boat stabilizer - Google Patents

Abstract

A hydrofoil boat stabilizer having a cross-sectional area with the configuration of a true hydrofoil is provided. The hydrofoil includes a slip-on yoke designed to compressively fit on a cavitation plate of a boat motor lower drive unit. A yoke-bridge limits expansion of the channel defined by the yoke when the hydrofoil is secured to the cavitation plate. The wings of the hydrofoil include at least one angle of attack, and preferably, a plurality of angles of attack. The hydrofoil is shaped to reduce drag and minimize cavitation, A low-drag surface is included on at least a portion of the outer surface of the hydrofoil.

Description

HYDROFOIL BOAT STABILIZER

PRIORITY CLAIM

This application claims priority to U.S. Provisional Application Serial. No. 61/651,178 as filed on 24 May 2012, entirety of which is incorporated herein by reference.

BACKGROUND

[0001] The present invention relates to a hydrofoil boat stabilizer having a true lifting airfoil/hydrofoil shape incorporated into the design, which provides lift to the stern of the boat. The hydrofoil boat stabilizer is attachable to a cavitation plate on the lower drive unit of a boat motor.

[0002] The skilled artisan understands that the drive system of a boat generates the forward thrust. The same skilled artisan also understands that the boat and drive system are fighting the forces of drag upon the boat as it rides low in the water. Thus, the higher in the water, or "on the plane," a boat rides, the less drag it encounters. Therefore, it is desirable to reduce the amount of boat drag.

[0003] Many forces exert drag on a boat. In particular, the greater degree of boat hull in contact with water increases drag. Therefore, getting a boat on plane faster will decrease drag. Providing lift to the lower drive unit will help get a boat on plane; however, stabilizers commonly used to lift the drive unit also introduce additional drag.

[0004] Therefore, a "right" true hydrofoil shape for a boat stabilizer is desired for a stabilizer. A true hydrofoil shape is a hydrofoil designed and tested by using aerodynamic/hydrodynamic design principles and procedures, such as the foil design software, XFOIL Subsonic Airfoil Development System, from the Massachusetts Institute of Technology, or a similar such program. A true hydrofoil shape improves performance, and reduces both cavitation and drag. Various hydrofoil designers have produced and tested several true hydrofoil shapes, each having different performance characteristics across a wide range of performance parameters at differing speeds, to include lift, drag, profile drag, cavitation, and laminar-to- turbulent transition. Some non-limiting examples of hydrofoil shapes include the NACA 63-209, Eppler E817, Eppler E818, Eppler E836, Eppler 837, Eppler E838, Eppler E874, Eppler E904, Eppler E908, and the Speers H105. The "right" true hydrofoil shape is one that is applicable for the particular performance characteristics desired for the boat, engine and boat stabilizer. For example, a performance characteristic might be a constant, total laminar flow across the entire hydrofoil wing section for a given speed range.

[0005] Hydrofoil lift characteristics are balanced against drag and cavitation resistance for given speeds. Preferably, the hydrofoil will control cavitation across a broad range of speeds/velocities. One example of hydrofoil performance is the HI 05 hydrofoil shape, which has a profile drag that is nearly constant as the laminar-to-turbulent transition point moves forward on the upper surface of the hydrofoil. Simultaneously, the laminar-to-turbulent transition point moves aft on the lower surface as flow speed increases. This results in the example HI 05 hydrofoil maintaining nearly the same total amount of laminar flow across it, thereby providing strong lift characteristics. By maintaining a constant laminar flow, the rapid formation and collapse of vapor pockets along the hydrofoil are reduced to a constant level, thereby reducing the opportunity for creation of additional drag due to cavitation. SUMMARY

[0006] In one embodiment, the current invention provides a slip-on hydrofoil. The slip-on hydrofoil comprises a yoke and a pair of wings. The yoke includes a center body defining a longitudinal channel therein. The longitudinal channel has a first and second side, and is open to the front of the center body. The yoke also includes a pair of open-ended slots oppositely disposed in each of the channel sides, and extending along a substantial length of the sides. The open-ended slots are capable of receiving a cavitation plate of a boat motor. The yoke includes a tail section integrally formed with the center body. The tail section covers a portion of the longitudinal channel. The yoke includes a contoured trailing edge defined by the tail section. The contoured trailing edge angles upwardly. The pair of wings are integrally joined with the yoke and project outwardly therefrom. Each of the wings has a leading edge and a trailing edge. The trailing edges of the wings are seamlessly integrated with the contoured trailing edge of the tail section. A plurality of securing devices disposed through the center body secure the slip-on hydrofoil to a cavitation plate. Additionally, a yoke-bridge maintains the preferred gap of the longitudinal channel defined by the yoke following attachment of the slip-on hydrofoil on the cavitation plate.

[0007] In one embodiment, the current invention provides a hydrofoil for use in conjunction with a cavitation plate. The hydrofoil includes a yoke having a center body. The center body defines a longitudinal channel having oppositely positioned walls and the walls defining or carrying oppositely positioned slots. The hydrofoil includes a pair of wings having a wing tip, a root, and a trailing edge. Each wing has a cross-sectional configuration of at least one true hydrofoil from the wing tip to the root, wherein the pair of wings joins to the yoke at the wing root. Non-invasive securing devices pass through the hydrofoil and contact the cavitation plate to secure the hydrofoil to the cavitation plate. Additionally, a yoke-bridge, secured to the yoke, spans the longitudinal channel.

[0008] In yet another embodiment, the current invention provides a minimum cavitation, low-drag hydrofoil. The minimum cavitation, low-drag hydrofoil comprises a yoke and a pair of wings. The yoke includes a longitudinal channel and a tail section. The longitudinal channel has a pair of oppositely positioned slots disposed in oppositely positioned walls. The tail section integrally covers a portion of the longitudinal channel. Each of the wings has a wing tip, a root, and a trailing edge. Each of the wings has a cross-sectional configuration of at least one true hydrofoil from the wing tip to the root. Each wing has at least one angle of attack. The pair of wings joins to the yoke at the root. There is a contoured trailing edge extending from the tail section and seamlessly integrated with the trailing edge of the wings. The contoured trailing edge on the tail section is a juncture of a contoured flow surface area and an upward sloping bottom. There is a drag reducing surface on the hydrofoil. There is at least one securing device for retaining said hydrofoil on a cavitation plate. Additionally, a yoke-bridge connecting the opposing walls of the longitudinal channel maintains the preferred gap of the longitudinal channel defined by the yoke following attachment of the slip-on hydrofoil on the cavitation plate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a bottom perspective view.

[0010] FIG. 2 is a bottom view.

[0011] FIG. 3 is a bottom perspective view depicting one installation of the yoke-bridge.

[0012] FIGS. 4A and 4B are perspective views of two embodiments of the yoke-bridge.

[0013] FIG. 5 is top view of the yoke-bridge,

[0014] FIGS. 6 A and 6B are front views of the embodiments in FIGS. 4A and 4B. [0015] FIG. 7 is a side view of the yoke-bridge depicting the leg.

[0016] FIG. 8 is a top perspective view of the hydrofoils with yoke-bridge installed and this FIG. depicts the optional drag reducing surface.

[0017] FIG. 9 is a side view of a hydrofoil positioned to slip onto the lower drive unit of a boat motor prior to installation of the yoke-bridge.

[0018] FIG. 10 is a bottom perspective view depicting an alternative embodiment of the yoke-bridge.

[0019] FIG. 11 is a schematic representation of an exemplary true hydrofoil shape.

DETAILED DESCRIPTION

[0020] Referring to FIGS. 1-10, the hydrofoil apparatus is illustrated and generally designated by the numeral 10. Hydrofoil 10 is designed as a slip-on hydrofoil having minimum cavitation with low-drag characteristics. As shown in FIG. 9, hydrofoil 10 will slip onto cavitation plate 12 of lower drive unit 14 of a boat motor. As depicted in the FIGS, hydrofoil 10 is the combination of yoke 16 and wings 18. Yoke 16 is designed to fit around cavitation plate 12 and lower drive unit 14 of a boat motor. A yoke-bridge 110 spans the opening of the yoke to maintain the desired gap defined by opposing sidewalls 36 and 38 (also referred to as channel first side 36 and channel second side 38). Over-tightening of securing devices 124 can place undue stress on yoke 16 by increasing the gap defined by sidewalls 36 and 38 potentially leading to premature failure of hydrofoil 10. Yoke-bridge 1 10 counters the tendency of users to overtighten securing devices 124 and substantially precludes expansion of the gap between sidewalls 36 and 38. U.S. Patent Application Ser. No. 12/826,412, filed on June 29, 2010 and published as U.S. Pub. No. 2001/0315063 on December 29, 2011, incorporated by reference herein, discloses a similar hydrofoil lacking the yoke-bridge improvement of the current invention. [0021] Regarding FIGS. 1-3, 8 and 10, yoke 16 includes center body 20, longitudinal channel 22, and tail section 24. Yoke 16 also includes front 26, aft 28, sides 30, top 32 and bottom 34 of center body 20. Front 26, aft 28 and sides 30 all have rounded edges transitioning to bottom 34. Additionally, front 26 and aft 28 are sloped towards sides 30, thereby reducing drag around yoke 16, One preferred embodiment positions yoke-bridge 1 10 on bottom 34 near the forward open end of yoke 16. However, yoke-bridge 110 may be optionally located on top 32 in a similar configuration.

[0022] Yoke 16 defines longitudinal channel 22 within center body 20. Longitudinal channel 22 opens to front 26 and aft 28. Longitudinal channel 22 has channel first side 36 and channel second side 38, which are oppositely positioned walls. Open-ended slots 40 and 42 are disposed in channel first and second sides 36 and 38, respectively. Open-ended slots 40 and 42 are oppositely positioned from each other. As illustrated, open-ended slots 40 and 42 are approximately centered on channel sides 36 and 38. However, open-ended slots 40 and 42 may be positioned above or below the depicted location by as much as about 25 percent without significant degradation to hydrofoil 10 performance. Open-ended slots 40 and 42 are sized to slip on cavitation plate 12 and around torque tab 44 affixed thereto.

[0023] Referring to FIGS. 1 and 3, open-ended slots 40 and 42 are capable of receiving cavitation plate 12. As illustrated, open-ended slots 40 and 42 extend along a substantial length of channel first and second sides 36 and 38, terminating near aft 28 of center body 20 at slot wall 46. Slot wall 46 provides a receiving block for cavitation plate 12 that prevents cavitation plate 12 from moving aft-wardly in open-ended slots 40 and 42 once hydrofoil 10 is slipped thereon. Although not illustrated, yoke 16 and longitudinal channel 22 are optionally adjustable to facilitate placement of hydrofoil 10 on different boat motors and cavitation plates 12. [0024] Extending from yoke 16 onto contoured flow surface area 48 of tail section 24 of hydrofoil 10 is yoke drag relief 50. Yoke drag relief 50 is wedge-like in its shape. Yoke drag relief 50 eliminates hydraulic impingement on hydrofoil 10 at the point where the water flow departs from cavitation plate 12 and lower drive unit 14 of a boat motor. Thus, yoke drag relief 50 reduces the drag acting upon hydrofoil 10.

[0025] Referring to FIGS. 1-3, 8 and 10 tail section 24 is integrally formed with yoke 16 across top 32 and center body 20 towards aft 28. Tail section 24 provides the connective support structure for yoke 16. A portion of tail section 24 covers longitudinal channel 22. Tail section 24 terminates beyond aft 28 of yoke 16 at contoured trailing edge 52. Near the forward end of yoke 16, yoke-bridge 110 spans longitudinal channel 22. Yoke-bridge 110 provides structural support to hydrofoil 10 following attachment of hydrofoil 10 to cavitation plate 12. Yoke-bridge 110 substantially precludes expansion of longitudinal channel 22 due to over-tightening of set- screws 124 or other securing devices 124 passing through threaded holes 86.

[0026] The portion of longitudinal channel 22 covered by tail section 24 is preferably about one-half of the total length of yoke 16 and tail section 24 combined, or less. As illustrated in FIGS. 1-3, 8 and 10, tail section 24 may cover a small portion of longitudinal channel 22 and open-ended slots 40 and 42.

[0027] Tail section 24 includes yoke drag relief 50. Yoke drag relief 50 provides for transition of fluid, such as water, from cavitation plate 12 and lower drive unit 14 of a boat motor over transition flow edge 54, and onto and along contoured flow surface area 48 and spine 56. Transition flow edge 54 is the transition point from yoke drag relief 50 and contoured flow surface area 48 and spine 56. Contoured flow surface area 48 and spine 56 provide water flow onto and over contoured trailing edge 52. Both contoured flow surface area 48 and spine 56 terminate at contoured trailing edge 52,

[0028] Extending from bottom 34 at aft 28 is upward sloping bottom 58 of tail section 24. With reference to FIGS, 8 and 10, contoured flow surface area 48 and upward sloping bottom 58 join together to form contoured trailing edge 52. Contoured trailing edge 52 is the juncture of contoured flow surface area 48 and upward sloping bottom 8. Contoured flow surface area 48 provides an upwardly angling flow direction as it approaches contoured trailing edge 52. Similarly, upward sloping bottom 58 provides an upwardly angling flow direction as it approaches contoured trailing edge 52. Upward sloping bottom 58 has a steeper upward slope than that of contoured flow surface area 48. The resulting flow of water, departing contoured trailing edge 52, has an overall reduction of turbulence, which in turn reduces the cavitation and drag imparted to hydrofoil 10.

[0029] As illustrated in FIG. 8, wings 18 have leading edge 60, trailing edge 62, wing tip 64 and root 66. Wings seamlessly and integrally join with yoke 1 at root 66. In particular, wings integrally join with center body 20 at root 66 and form upper flow channel 68 where upper surface of wings 18 join top 32 of yoke 16. Upper flow channel 68 channels water in the transition zone between wing root 66 and yoke 16 towards aft 28 and tail section 24. Seamless integration of trailing edge 62 and contoured trailing edge 52 helps to maintain laminar flow of water over trailing edge 62 and contoured trailing edge 52. Thus, the seamless integration of trailing edge 62 and contoured trailing edge 52 provides for a low-drag release of the water from the hydrofoil tail section thereby minimizing drag.

[0030] As illustrated in FIG. 11, wings 18 have cross-sectional shape 70 that is the configuration of a true hydrofoil. Non-limiting examples of true hydrofoils include hydrofoils having the designation of NACA 63-209, Eppler E817, Eppler E818, Eppler E836, Eppler 837, Eppler E838, Eppler E874, Eppler E904, Eppler E908, and Speers H105. Some of the decision parameters used to select the true hydrofoil are based upon the speed, lift, and drag characteristics for which the hydrofoil will be utilized. In one preferred embodiment, the Speers H105 hydrofoil shape satisfies all of the desired characteristics of lift and drag for the different speeds hydrofoil 10 is to operate.

[0031] Preferably, wings 18 continuously retain the cross-sectional configuration of the true hydrofoil from wing tip 64 through root 66, including a plurality of angles of attack, but at least one angle of attack. Alternatively, the true hydrofoil shape transitions from a first true hydrofoil shape to at least one other true hydrofoil shape for each angle of attack based upon the broad spectrum of performance parameters desired for hydrofoil 10. Thus, wings 18 provide for at least one lifting segment having at least one angle of attack.

[0032] As illustrated in FIGS. 1-3, 8 and 10, wings 18 have a swept-back configuration. Near root 66, wings 18 have forward section 82 seamlessly extending from yoke 16. Forward section 82 sharply sweeps back from yoke 16 towards aft 28, and transitions into outer section 84 near transition point 80.

[0033] Following positioning of hydrofoil 10 on cavitation plate 12, yoke-bridge 110 is secured to hydrofoil 10. In a preferred embodiment as depicted in FIGS. 1-3 and 8, yoke-bridge 110 is secured to bottom 34 of yoke 16 in a position near the opening of yoke 16. Preferably, bottom 34 has a recessed area 116 conforming to the outline and thickness of yoke-bridge 110. Thus, when installed in recessed area 116, yoke-bridge 110 does not interrupt fluid flow over hydrofoil 10, i.e. yoke-bridge 110 and bottom 34 provide a generally flush surface. [0034] In one embodiment depicted in FIG. 10, securing devices 124 passing through yoke- bridge holes 119 into center body threaded holes 122 located in bottom 34 retain yoke-bridge 110 to hydrofoil 10. In this embodiment, center body threaded holes 122 preferably terminate within hydrofoil 10.

[0035] In a preferred embodiment, bottom 34 has at least two molded center body slots 120, one on each side of yoke 16, i.e. on each side of longitudinal channel 22. Preferably molded center body slots 120 align with threaded holes 86 passing from the exterior of center body 20 to center body slots 120. Thus, threaded holes 86 pass from the exterior of said center body 20 and open into longitudinal channel 22 intersecting center body molded slots 120. The entire length of threaded hole 86 need not be threaded. In the preferred embodiment, yoke-bridge 110 has two legs 1 12. Each leg has a hole 118 generally corresponding in diameter to threaded holes 86. When installed each leg 112 is positioned within a center body slot 120 with hole 118 aligned with threaded hole 86. Threaded holes 86 and 122 may be in the form of holes directly carrying threads 87 or holes containing threaded inserts (not shown).

[0036] Securing devices 124 passing through threaded holes 118 and contacting cavitation plate 12 positioned within longitudinal channel 22 secure Yoke 16 to cavitation plate 12, Securing devices 124 may be set-screws or other similar low-profile devices, As illustrated in the FIGS., each side of yoke 16 has at least one threaded hole 86 passing through center body 20. Although depicted in the FIGS, as having has two or three threaded holes 86 per side, hydrofoil 10 may have only a single threaded hole 86 per side. A single securing device per 124 passing through one threaded hole 86 per side will apply sufficient force to secure hydrofoil 10 to cavitation plate 12. As depicted in the FIGS,, with hydrofoil 10 positioned on cavitation plate 12, threaded holes 86 align with edge 88 of cavitation plate 12. Following positioning of yoke 16 on cavitation plate 12 and positioning of yoke-bridge 110 on hydrofoil 10, tightening of securing devices 124 secures yoke 16 (and hydrofoil 10) to edge 88. Preferably, securing devices 124 compressively engage edge 88 of cavitation plate 12, By using compressive force to secure yoke 16, securing devices 124 non-invasively securing yoke 16 to cavitation plate 12.

[0037] In the preferred embodiment, securing devices 124 pass through threaded holes 86 and yoke-bridge holes 1 18 thereby securing yoke-bridge 110 to hydrofoil 10. Although depicted as round holes, holes 118 may be elliptical openings or elongated slots. As depicted in FIG. 3, at least one securing device 124 on each side of hydrofoil 10 will pass through at least one yoke- bridge hole 118. Although depicted has having a width corresponding to only one threaded hole 86, yoke-bridge leg 112 may have a width sufficient to cover two or more threaded holes 86. In that instance, leg 112 will have either a corresponding hole 118 for each threaded hole 86 or a slot-like opening of sufficient length to correspond to the corresponding threaded holes 86.

[0038] The configuration of yoke-bridge 110 substantially precludes over-tightening of securing devices 124. Over-tightening of securing devices 124 without yoke-bridge 110 in place applies unopposed force to cavitation plate 12. The force applied to cavitation plate 12 also translates to threads 87 within holes 86 thereby increasing the distance between opposing sidewalls 36 and 38 until the installer no longer tightens securing devices 124. Increasing the distance between sidewalls 36 and 38 places stress on the overall structure of hydrofoil 10. However, with yoke-bridge 110 installed, yoke-bridge legs 1 12 within slots 120 oppose the outward force resulting from tightening of securing devices 124 passing through threaded holes 86 and contacting cavitation plate 12. Further, yoke-bridge 110 reduces the likelihood of overtightening securing devices 124 within threaded holes 86. Since yoke-bridge 110 opposes or limits separation of opposing sidewalls 36 and 38, tightening of securing devices 124 applies increased force to cavitation plate 12. With yoke-bridge 110 installed, the increased force translates to a sensed increase in torque on securing device 124 without spreading of yoke 16. As a result, the installer will readily detect increased resistance during tightening of securing devices 124 as opposed to the continued spreading of the gap between opposing sidewalls 36 and 38. Thus, yoke-bridge 110 maintains the designed separation of opposing sidewalls 36 and 38 and enhances the structural integrity of hydrofoil 10.

[0039] An alternative embodiment of yoke-bridge 110 is depicted in FIGS. 4B and 6B as a flat plate with securing devices 124 passing through yoke-bridge holes 119 into threaded holes 122 within bottom 34. Yoke-bridge holes 1 19 are depicted as round holes; however, yoke bridge holes 1 19 may also be in the form of an elliptical opening or elongated slots. When installed, this embodiment also maintains the designed gap between opposing sidewalls 36 and 38 and provides opposition to over-tightening of securing devices 124 passing through threaded holes 86. Thus, both embodiments precluded undesired expansion of longitudinal channel 22 and separation of yoke 16 when securing hydrofoil 10 to cavitation plate 12.

[0040] As depicted in FIG. 8, exposed outer surface 90 of hydrofoil 10 may have an optional textured surface 93. The preferred texturing helps maintain laminar flow by reducing the magnitude of turbulent separation of the water from exposed outer surface 90. The reduced magnitude of the turbulent separation also reduces the localized drag experienced by hydrofoil 10. In one optional embodiment, exposed outer surface 90 has a plurality of extremely small outward projections 93 that have varying height and placement across exposed outer surface 90, thereby creating the drag reducing surface 93. Drag reducing surface 93 is analogous to the denticles found on sharkskin. Preferably, drag reducing texture 93 of exposed outer surface 90 is molded directly into surface 90; however, but it may also be applied thereto. [0041] If desired, the entire exposed outer surface 90 of hydrofoil 10 may have drag reducing texture 93. Alternatively, only particular segments of hydrofoil 10 may have drag reducing texture 93. For example, drag reducing texture 93 on exposed outer surface 90 may be limited to upper surface 92 of tail section 24 and to wing upper surface 94 of wings 18.

[0042] Optionally, hydrofoil 10 may also include a pair of stabilizing fins 130 positioned on bottom 34. Preferably, stabilizing fins 130 are molded directly into hydrofoil 10.

[0043] During operation of a boat having hydrofoil 10 installed thereon, water flowing over hydrofoil 10 transitions between laminar and turbulent. Turbulent flow creates drag and increases the profile drag, thereby reducing the performance of hydrofoil 10. By using wings 18 with a cross- sectional shape configuration of the true hydrofoil, such as the Speers HI 05, the transition phase of the laminar-to-turbulent is such that the overall amount of laminar flow remains constant across wings 18 as the speed varies. Thus, as the speed increases, the laminar- to-turbulent transition on wing upper surface 94 moves toward leading edge 60, while the laminar-to-turbulent transition on wing lower surface 96 moves toward trailing edge 62. This transitional action keeps cavitation to a minimum and constant level, thereby minimizing and/or reducing drag. The addition of drag reducing texture 93 to exposed outer surface 90 reduces the impact of the turbulent flow aft of the laminar-to-turbulent transition on wing upper surface 94, and/or wing lower surface 96. Thus, reduction in localized drag and overall drag provides increased performance.

[0044] Other embodiments of the current invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. Thus, the foregoing specification is considered merely exemplary of the current invention with the true scope thereof being defined by the following claims.

Claims

What is claimed is:

1. A hydrofoil comprising :

a yoke having a center body;

a longitudinal channel defined by said center body, said longitudinal channel having oppositely positioned walls defining oppositely positioned slots therein;

a pair of wings having a wing tip, a root, and a trailing edge, each said wing having a cross-sectional configuration of at least one true hydrofoil from said wing tip to said root, wherein said pair of wings are joined to said yoke at said root;

at least one non-invasive securing device suitable for retaining said hydrofoil on a cavitation plate;

a yoke-bridge spanning said longitudinal channel, said yoke bridge secured to said yoke.

2. The hydrofoil of claim 1 , wherein said center body has a recessed area corresponding to the outline and thickness of said yoke-bridge.

3. The hydrofoil of claim 1, further comprising at least two center body slots, wherein at least one center body slot is positioned on each side of said longitudinal channel, and said yoke- bridge has at least two legs, each leg of said yoke-bridge positioned within a center-body slot when said yoke-bridge is secured to said yoke.

4. The hydrofoil of claim 3, wherein said yoke-bridge substantially precludes expansion of said longitudinal channel when said hydrofoil is secured to a cavitation plate.

5. The hydrofoil of claim 3, further comprising at least one threaded hole on each side of said center body, said threaded hole passing from the exterior of said center body and opening into said longitudinal channel, wherein each yoke-bridge leg has at least one hole therein, when said yoke-bridge is secured to said hydrofoil at least one hole in said yoke-bridge leg aligns with at least one threaded hole passing from the exterior of said center body and opening into said longitudinal channel.

6. The hydrofoil of claim 5, further comprising securing devices passing through said threaded holes passing from the exterior of said center body and opening into said longitudinal channel, said securing devices passing through said holes in said yoke-bridge legs thereby retaining said yoke-bridge on said hydrofoil.

7. The slip-on hydrofoil of claim 6, wherein when said hydrofoil is installed on a cavitation plate said securing devices compressively engage an edge of said cavitation plate.

8. The hydrofoil of claim 6, wherein said yoke-bridge substantially precludes expansion of said longitudinal channel when said hydrofoil is secured to a cavitation plate.

9. The hydrofoil of claim 1, further comprising at least two center body threaded holes, wherein at least one center body threaded hole is positioned on each side of said longitudinal channel, and wherein said yoke-bridge has at least two holes, said yoke bridge secured to said yoke by threaded fasteners passing through said yoke-bridge holes into said center body threaded holes.

10. The hydrofoil of claim 9, wherein said yoke-bridge substantially precludes expansion of said longitudinal channel when said hydrofoil is secured to a cavitation plate.

11. The slip-on hydrofoil of claim 10, further comprising at least one threaded hole passing from the exterior of said center body and opening into said longitudinal channel, securing devices positioned within said threaded holes and wherein when said hydrofoil is installed on a cavitation plate said securing devices compressively engage an edge of said cavitation plate thereby retaining said hydrofoil on a cavitation plate.

12. The hydrofoil of claim 1, further comprising a tail section integrally formed with said center body, said tail section defining a contoured trailing edge terminating into a trailing edge peak wherein said contoured trailing edge seamlessly integrates with said trailing edge of said wings.

13. A slip-on hydrofoil comprising:

a yoke including:

a center body defining a longitudinal channel therein, wherein said longitudinal channel has a first and second side and is open to a front of said center body;

a yoke-bridge spanning said longitudinal channel;

a pair of open-ended slots oppositely disposed in each of said channel sides and extending along a substantial length of said sides, wherein said open-ended slots are capable of receiving a cavitation plate of a boat motor;

a tail section integrally formed with said center body and covering a portion of said longitudinal channel;

a contoured trailing edge defined by said tail section, said contoured trailing edge angles upwardly into a trailing edge peak;

a pair of wings integrally joined with said yoke and projecting outwardly therefrom, said pair of wings having a leading edge and a trailing edge, wherein said trailing edge is seamlessly integrated with said contoured trailing edge of said tail section; and,

at least one non-invasive securing device suitable for retaining said hydrofoil on a cavitation plate.

14. The slip-on hydrofoil of claim 13, wherein said center body has a recessed area corresponding to the outline and depth of said yoke-bridge.

15. The slip-on hydrofoil of claim 13, further comprising at least two center body slots, wherein at least one center body slot is positioned on each side of said longitudinal channel, and said yoke-bridge has at least two legs, each leg of said yoke-bridge positioned within a center- body slot when said yoke-bridge is secured to said yoke.

16. The slip-on hydrofoil of claim 15, wherein said hydrofoil substantially precludes expansion of said longitudinal channel when said hydrofoil is secured to a cavitation plate.

17. The slip-on hydrofoil of claim 15, further comprising at least one threaded hole passing from the exterior of said center body and opening into said longitudinal channel, wherein each yoke-bridge leg has at least one hole therein, when said yoke-bridge is secured to said hydrofoil at least one hole in said yoke-bridge leg aligns with at least one threaded hole passing from the exterior of said center body and opening into said longitudinal channel.

18. The slip-on hydrofoil of claim 17, further comprising securing devices passing through said threaded holes passing from the exterior of said center body and opening into said longitudinal channel, said securing devices passing through said holes in said yoke-bridge legs thereby retaining said yoke-bridge on said hydrofoil.

19. The slip-on hydrofoil of claim 18, wherein when said hydrofoil is installed on a cavitation plate said securing devices compressively engage an edge of said cavitation plate.

20. The slip-on hydrofoil of claim 18, wherein said hydrofoil substantially precludes expansion of said longitudinal channel when said hydrofoil is secured to a cavitation plate.

21. The slip-on hydrofoil of claim 13, further comprising at least two center body threaded holes, wherein at least one center body threaded hole is positioned on each side of said longitudinal channel, and wherein said yoke-bridge has at least two holes, said yoke bridge secured to said yoke by threaded fasteners passing through said yoke-bridge holes into said center body threaded holes.

22. The slip-on hydrofoil of claim 21, wherein said yoke-bridge substantially precludes expansion of said longitudinal channel when said hydrofoil is secured to a cavitation plate.

23. The slip-on hydrofoil of claim 22, further comprising at least one threaded hole passing from the exterior of said center body and opening into said longitudinal channel, securing devices positioned within said threaded holes and wherein when said hydrofoil is installed on a cavitation plate said securing devices compressively engage an edge of said cavitation plate thereby retaining said hydrofoil on a cavitation plate.

24. The slip-on hydrofoil of claim 13, wherein said contoured trailing edge seamlessly integrates with said trailing edge of said wings.