Bathtub boat
Racing Bathtub boats are small watercraft designed around bathtubs or close facsimiles and are used in bathtub races.
Boat design
Early boats were whimsical and crafted from a variety of materials. Today, most racing bathtub boats are monohull planer types with outboard motors. The rules restrict the engine to 8 hp (6 kW), and the weight to a minimum of 350 lb (159 kg) including driver. There are three classes of bathtub boats: Stock, Modified, and Super-Modified. A form resembling a roll-top tub must be an integral part of the structure. Most tubbers make their "tub" by using a bathtub as the model mold to lay down a fiberglass mold. Stock motors must be an unmodified stock engine, but can be tuned by adjusting the timing. Modified motors can only modify the lower leg and propeller. Super Modified can modify the entire engine as long as factory parts are used.
