High Speed Boat Hull

This invention relates to a boat hull and, more particularly, to a hull of the planing type.

Flat bottom hulls are considered to have good planing characteristics due to the fact that there is a minimum amount of wetted surface and as a result there is a decrease in drag as the boat speed increases. However, flat bottom hulls lack stability, especially on turning, and also have a tendency to produce a rough ride in choppy water

On the other hand, V-bottom hulls, when used for planing, are generally formed with a relatively deep V at the bow which flattens out towards the stern. The V-shaped hull has the ability of being able to cut through heavy seas, although as the V cuts down into the water, the water is displaced along the V and has a tendency to slap against the bottom of the hull. Furthermore, the V bottom hull lacks lateral or rolling stability, particularly in the forward portion of the hull. Therefore the extent of the V in the hull is generally limited to the forward portion and does not extend generally aft of midship.

As an improvement U.S. Pat. No. 3,776,108 teaches a hull which has an overall V-shape with Vs of lesser depth formed on each side of the center line of the keel. This hull increases lateral stability but acts to increase the amount of wetted surface so that the planing characteristics of this hull are adversely affected.

As another improvement, U.S. Pat. No. 3,930,455 teaches a hull which has a pair of upwardly arched longitudinal channels on each side of the keel portion. Although this hull improves the planing characteristics, the hull is subject to capsizing during a relatively high speed type turn.

An object of this invention is to provide a boat hull which has improved planing characteristics, stability and handling.

Another object of this invention is to provide a hull which captures a pair of columns of air under its hull and gradually laterally releases the columns as the air passes to the stern to increase stability.

Another object of this invention is to provide a shallow V-shaped keel adjacent the stern of the hull, on which the hull can plane.

These and other objects and features of advantage will become more apparent after studying the following description of the preferred embodiment of my invention, together with the appended drawings.

FIG. 1 is a bottom view of my novel boat hull showing the preferred embodiment of my invention.

FIG. 2 is a side elevation of the boat hull of FIG. 1.

FIG. 3 is a section taken on line 3--3 of FIG. 1.

FIG. 4 is a section taken on line 4--4 or line 4a--4a of FIG. 1 or anywhere therebetween.

FIG. 5 is a section taken on line 5--5 of FIG. 1.

FIG. 6 is a section taken on line 6--6 of FIG. 1.

FIG. 7 is an end or stern view of the hull.

The drawings illustrate a boat hull which can be preferably formed as a hollow shell by molding reinforced plastic material, such as a mixture of thermosetting resin and glass fibers. In general, the hull is provided with a pointed bow, but could also be curved, and is provided with a generally squared off stern 12. The hull has sloping outboard bulkheads 13 and 14, which curve towards the bow 11 and the stern 12, forming at line 4--4 the widest portion or beam and, as is common in the art, is called the midship section. The bulkheads 13 and 14 are connected with my novel bottom 15. Of course, the hull is symmetrical about a center line 30.

In accordance with the invention, the bottom is formed of a complex warped surface having particular features. The bottom having keep portion 21 which, for lack of a better description, is referred to as a modified V having a pair of inclined surfaces 21a and 21b. From station 4a--4a (lines 4a--4a) to the bow 11 the keel has a V shape, as shown in FIGS. 3 and 4. The V shape extends laterally on each side of the center line 30 to lines 23 and 24. Aft of station 4a--4a of FIG. 1, the keel 21 forms a swept back wing shaped planing surface or appendage 25 as shown in FIGS. 5, 6, and 7. The planing surface 25 starts as a point at station 4a--4a and widens as it extends aft. At high speeds, I believe the hull makes contact with the water only with the planing surface 25. As shown in FIGS. 5, 6, and 7, the cross-section of surface 25 is preferably gull shaped in that lines 26 and 27 are elevated with respect to lines 28 and 29 which, in turn, are elevated with respect to the center line 30 of the keel. One observes that converging vertical surfaces extend from lines 28 and 29, respectively, to surfaces 21a and 21b. As an alternate, a flat surface could be used between lines 28 and 30 and lines 29 and 30, making a V shape somewhat shallower than the V shape forward of station 4a--4a. One will notice that lines 23 and 24 extend from station 5--5 of FIG. 1 to almost the bow where the lines fade into the rounded hull shape formed adjacent the bow. Laterally from each line 23 and 24 extends a surface 23a and 24a to lines 31 and 32, respectively, which surfaces 23a and 24a are horizontal in a transverse direction to a base plane represented by lines 8 in the various figures. Aft of station 5--5 the keel portion has its surfaces 21a and 21b unbroken or smooth to lines 33 and 34. Dash lines 33a and 34a in FIG. 5 represent this condition. In other words, if one looks forward at section 5--5, one will see the configuration in FIG. 5 represented by the solid lines, and if one looks aft, one will see the configuration represented by the dash lines together with the obvious solid lines. Outboard from lines 33 and 34, respective surfaces 33a and 34a are formed to lines 35 and 36, which surfaces slope in the outboard direction towards the base plane whereby lines 35 and 36 are lower than respective lines 33 and 34. Outboard of lines 35 and 36, respective tunnels 37 and 38 are formed which have transverse cross-sections that are substantially uniform fore and aft of the hull. In other words, lines 35 and 36 and lines 41 and 42 are substantially parallel to the center line 30. The respective upper surfaces of tunnels 37 and 39 are parallel in a transverse direction to the base plane 8, and almost parallel in the longitudinal direction to base plane 8. The side surfaces of tunnels 37 and 38 are substantially vertically disposed surfaces. However, the outboard vertical surfaces of the respective tunnels aft of station 4a--4a transform to downward sloping surfaces 43 and 44. Outboard surfaces 45 and 46 are horizontal in the transverse direction outboard of lines 41 and 42. Then aft of station 4a--4a, surfaces 43 and 45 cross to form line 47 as surfaces 44 and 46 cross to form line 48.

One observes that the bottom of my novel hull is substantially flat. However, I have provided at the center line a relatively shallow V-shaped keel which transform to a still shallower V-shape in the aft portion. The purpose of this is to reduce further the wetted surface at high speed. I have provided a pair of tunnels 37 and 38 of substantially uniform cross-section fore and aft and having vertical side walls to insure capturing and ramming the air therein, causing the hull to rise quickly as the speed increases. The acute angle, as shown in FIGS. 3, 4, 5, 6, and 7 represented by lines 35 and 36, provide outboard "keels" which contact the water when the hull leans, as in a turn, to help keep it erect. To further prevent the hull from flipping at high speeds, I have provided the sloping surfaces 43 and 44 to relieve the upward force of the air under the hull at the aft end. Since this force is lower, there is less tendency to cause a hull to flip in a tight high-speed turn. I have provided a hull which is more stable and has better control than a flat bottom hull, while still maintaining substantially all of the desirable features of a flat bottom hull. My hull may be used with either an inboard or outboard motor.

Having described the preferred embodiment of my invention one, after reading and studying the above description of the preferred embodiment, can devise other embodiments without departing from the spirit of my invention. Therefore, my invention is to be considered limited only to the scope in the appended following claims.