motorboat

Small, waterborne craft for pleasure cruising or racing, powered by a petrol, diesel, or gas-turbine engine. A boat not equipped as a motorboat may be converted by a detachable outboard motor. For increased speed, such as in racing, motorboat hulls are designed to skim the water (aquaplane) and reduce frictional resistance. Plastics, steel, and light alloys are now used in construction as well as the traditional wood.

In recent designs, drag is further reduced with hydrofins and hydrofoils, which enable the hull to rise clear of the water at normal speeds. Notable events in motorboat or ‘powerboat’ racing include the American Gold Cup in 1947 (over a 145 km/90 mi course) and the Round-Britain race in 1969.