In selecting the right boat for your needs, consider the type of activity for which you plan to use it, such as water skiing, fishing, cruising, or weekend outings. You also need to consider the type of water on which it will be used, such as rivers, lakes, open ocean, or the Great Lakes. The boat should be large enough to safely handle the number of people on a normal outing. Any boat equipped with propulsion machinery is a motorboat. Motorboats are divided into four classes according to length.
Many states also use the classes to establish registration fees and to number motorboats.
Shown here are examples of boats in the four classes. Length A motorboat is measured from end to end along the centerline or parallel to the centerline. The measurement is from the outside of the hull and does not include outboard motors, brackets, other attachments or similar fittings. A displacement hull moves through the water, while a planing hull is designed to skim on top of the water and can travel at a much higher speed. Each design has its limitations and advantages.