Abstract:
A pontoon boat having enhanced handling characteristics includes a deck, a central pontoon mounted to said deck, two outer pontoons mounted to said deck on respective opposite sides of said central pontoon, and a motor, wherein the central pontoon extends below the outer pontoons to create a V-shaped hull, and the motor is capable of causing said center and outer pontoons to plane during normal operation.

Description:
TECHNICAL FIELD 
     This invention relates to the art of pontoon boats. In particular, the invention relates to a high performance pontoon boat with characteristics that simulate that of a planing V-hull boat. 
     BACKGROUND ART 
     A popular type of boat is a pontoon boat. A pontoon boat includes, generally, pontoons that support a boat deck that, in turn, accommodates the passengers. Pontoons on such boats are generally designed as displacement structures, meaning that they support the weight of the boat and passengers by displacement of water, even when the boat is moving through the water at normal, design, operating speeds. In contrast, another type of boat hull is designed to support the weight of the boat by the kinematical forces applied to the hull by the water when the boat is moving at operating speeds. This latter type of hull is commonly known as a “planing” type of hull. 
     The planing type of hull is generally used for boats that operate at higher speeds and require more maneuverability, such as a boat for pulling a water skier. Users of pontoon boats, however, often want to run at higher speeds, for example, to pull water skiers. While it is not difficult to provide a pontoon boat with an engine having the horsepower to drive a pontoon boat at higher speeds, it has been difficult to provide a pontoon hull with handling characteristics similar to those of a V-hull such that the boat can be safely used in higher-speed activities. 
     A typical problem with a pontoon boat is its tendency to rotate toward the outside of a turn. This is an unstable motion, which if done at high speeds can be very dangerous. A planing type V-hull naturally tends to rotate toward the inside of a turn, which lends stability to that type of hull and allows it to be used at higher speeds. Thus, there is a need for a higher powered, sport type pontoon boat that handles safely at higher speeds. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide an improved sport-type pontoon boat that provides handling characteristics similar to those of a sport boat or V-hull boat with a planing hull. In accordance with the invention, the pontoons of a pontoon boat having an engine of adequate horsepower to operate normally at planing speeds are arranged with respect to each other and to the boat deck such that the hull exhibits handling characteristics similar to those provided by a V-hull. Alternatively the pontoons are further provided with planing elements that enhance the V-shape of the hull. 
     In a preferred embodiment, the boat hull is provided with three, generally parallel, pontoons that act as displacement hulls when the boat is stationary or operating at low speeds. The center pontoon, however, is configured such that when all three pontoons are considered, the overall cross sectional shape of the hull is that of a “V.” Combination of this hull with an engine capable of causing the boat to reach planing speed results in a highly maneuverable pontoon boat. 
     In the traditional pontoon boat, the pontoons are generally cylindrical on the lower half. In some designs (e.g., U.S. Pat. No. 5,784,977), the surface is not strictly cylindrical and may include planar components. While other configurations are possible, in the preferred embodiment of the invention, the pontoons are also generally cylindrical on the lower half, but the diameter of the central pontoon is larger than those of the outer two pontoons. The larger central pontoon and the smaller flanking pontoons are mounted to the boat deck to provide a V-shape to the overall configuration of the hull. In one embodiment, the larger central pontoon is sufficient to generate the V-shape if the tops of the cylindrical pontoons, or the continuations of the cylindrical shape of the lower part of the pontoon are aligned. 
     In accordance with an alternative feature of the invention, the central pontoon of larger diameter is mounted to the deck lower than the outer pontoons, which further emphasizes the overall V-shape of the hull. 
     In accordance with a still further feature of the invention, the pontoons are provided with lifting strakes that are angled upwardly to further enhance the V-shaped hull configuration and to provide enhanced handling characteristics. 
     It is an object of this invention to provide a pontoon style boat that has handling characteristics similar to those of a boat having a V-shaped planing hull. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a pontoon boat in accordance with the invention. 
         FIG. 2  is a transverse cross section of the deck and pontoons of the boat of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the drawing figures,  FIG. 1  illustrates a pontoon boat  2  in accordance with the invention. The pontoon boat  2  includes a deck  4  and at least three pontoons to support the weight of the boat in water. Pontoon  6  extends longitudinally and is located transversely in the center of the boat. Two additional pontoons  8  extend parallel to pontoon  6  and are located symmetrically on either side of pontoon  6 . A motor  9  may be mounted to the central pontoon. 
     To provide the pontoon boat of the invention with handling characteristics similar to those of a planing V-hull, the pontoons  6  and  8  are configured and positioned with respect to each other to provide an overall V-hull configuration, and the boat is powered by a motor  9  that is large enough to drive the boat at planing speeds during normal operating conditions. 
     One feature of the arrangement shown in  FIG. 2  is that the diameter of the center pontoon  6  is larger than the diameters of the outer pontoons  8 . A pontoon is primarily a displacement-type structure, and it will be appreciated that pontoon  6  is capable of displacing more water than either of the outer tubes. More importantly, however, pontoon  6  is mounted with respect to outer pontoons  8  such that it extends further into the water than do the pontoons  8 . By these features, the overall configuration of the three pontoons is that of a “V.” 
     Another feature of the hull in accordance with the invention is the use of lifting strakes on each of the pontoons to further simulate a V-shaped planing hull and to provide handling characteristics of such a hull. Thus, pontoon  6  includes strakes  10 , and pontoons  8  include strakes  12 . These strakes extend along the pontoons for the major part of their lengths, and taper toward the pontoon surface near the bow of the boat. The strakes are generally flat, rectangular surfaces and are located and oriented to provide the desired handling characteristics. The generally flat strakes are supported by vertical surfaces  14  and  16 , respectively. These vertical surfaces mainly support the strake surfaces but must also be configured to reduce drag. In the preferred embodiment, the vertical surfaces  14  and  16  are solid surfaces whereby the strake and the support are essentially triangular in cross section as shown in the figures. 
     While the boat  2  may be of almost any length, in preferred embodiments the boat is from 18 to 32 feet in length and more preferably 22 to 26 feet in length. The diameters of the pontoons vary according to the design-weight of the boat, and for a boat of 18 to 32 feet, the diameter of the center pontoon would be from 20 to 32 inches and preferably from 25 to 27 inches. The diameters of the outer pontoon may be 18 to 30 inches and preferably 23 to 25 inches. In a specific preferred embodiment, a boat of 22 to 26 feet would have a central pontoon of 25-inch diameter and outer pontoons of 23-inch diameter. In a second preferred embodiment, a boat of 22-26 feet in length would have a central pontoon of 27-inch diameter and outer pontoons of 25-inch diameter. In a third preferred embodiment of a boat 22-26 feet, the diameter of the outer pontoons would be 23 inches and that of the center pontoon 27 inches. 
     As noted, the central pontoon is mounted such that it extends further into the water than the outer pontoons. In a preferred arrangement, the central pontoon is mounted such that its bottom surface is 2 to 8 inches below the bottom surfaces of the outer pontoons. In a most preferred embodiment, the bottom surface of the central pontoon is 5 to 5¼ inches below the bottom surface of the outer pontoons. The outer pontoons are mounted laterally with respect to the central pontoon such that the angle of a line connecting the lowermost parts of the central and outer pontoons is 2 to 22 degrees and preferably about 7.5 degrees with respect to the horizontal. 
     The strakes  10  and  12  are designed to provide additional surface area to allow the hull of the invention to plane more easily and to simulate a V-hull. Thus, the strakes  10  on the central pontoon are placed at a smaller angle with respect to the horizontal than the strakes  12 . The surface of strake  10  may be placed at an angle of from 7 to 10.5 degrees with respect to the horizontal and is preferably about 8.7 degrees. The strake  12  may be placed at an angle of from 21 to 32 degrees and is preferably about 26.4 degrees with respect to the horizontal. 
     The horizontal extent of the strakes depends on the required surface area. For a boat of 22-26 feet in length, the strakes on the smaller pontoons would be from about 4.5 to about 5.5 inches in width and preferably about 5 inches. In the preferred embodiment, the outer edge of the strake is about 12¼ inches from the center of the smaller pontoon. The strakes on the larger, central pontoon would be from about 6.4 inches to about 7.7 inches in width and preferably about 7 inches. In the preferred embodiment, the outer edge of the strake is about 13 inches from the center line of the central pontoon. 
     The provision of a motor adequate to cause the pontoons to achieve planing speeds is important to achieving the desired handling characteristics. This feature may be defined by the ratio of weight to horsepower, which in the preferred embodiment is about 31 pounds per horsepower or less. Thus, if one considers the weight of the boat, motor, average fuel and at least one occupant on the one hand and the indicated horsepower of a motor that would ordinarily be used on this type of boat on the other, it requires at least one horsepower per 31 pounds to drive the described hull at planing speeds to achieve the desired handling characteristics of a boat according to the invention. In a more preferred embodiment, for boats 20-26 feet in length, the pounds-per-horsepower should be less than about 21 and more preferably less than about 19. 
     In a specific embodiment of the invention, a 24 foot pontoon boat has a center pontoon of 27 inches, outer pontoons of 23 inches, a dry weight of 2,715 pounds and is powered by a 225 horsepower V-6 outboard motor. In this embodiment, the bottom of the center pontoon is about five inches below the bottom the outer pontoons. 
     It will be further appreciated that the motor  9  will ride lower in the water than in a pontoon boat where the center tube is not deeper than the outer pontoons. 
     Modifications within the scope of the appended claims will be apparent to those of skill in the art.