Hoyt Daniel, age 15, of Baltimore, Md., for his question:
WHICH TYPE OF MOTORBOAT RACING IS FASTEST?
Motorboat racing is a sport involving competition between craft" powered usually by inboard or outboard internal combustion engines. In the United States, craft are assigned to a variety of classes on the basis of such elements as hull form and type and size of engine. The two types of speed racing hull, or boat frame, are the runabout and the hydroplane.
The runabout is a V bottom craft useful also for everyday utility boating, which when in motion, pushes through the water. They hyudroplane has a flat or concave bottom molded into a series of steps or fitted with fin like lateral protrusions known as sponsons or hydrofoils. At high speeds the hull of a hydroplane rises out of the water and is supported largely on its steps or hydrofoils.
Because the hydroplane travels over rather than through the water, it is a much faster boat than the runabout. The two craft seldom compete against each other on equal terms.
The speeds attained by racing runabouts and hydroplanes vary widely. The measured mile record for propeller driven, unlimited hydroplanes, set in 1962 by the American boat "Miss U.S.I." is 200.419 miles per hour. The record for an outboard hydroplane, set in 1984 by the American boat "America's Challenge, " is 157 miles per hour.
The world waterspeed record, set in 1978 by the Australian craft "Spirit of Australia" is 319.63 miles per hour.
Both the runabouts and hydroplanes may be propelled by inboard motors, that is, engines located within the hull, or by outboard motors, that is, power plants attached to the stern of the boat, or by inboard engines with outboard drive, known as inboard outboard (IO) or stern drive engines.
Classes within the inboard and outboard categories are based on the number of cubic inches of air displacement by the pistons of each motor.
Motorboat racing in the United States is supervised by the American Power Boat Association (APBA), which was founded in 1903. Commissions within the APBA are the outboard, inboard, stock outboard, unlimited power boat, cruiser, outboard pleasure craft, drag, modified outboard and off shore commissions.
The ruling body of international competition is the Union of International Motorboating, with headquarters in Ostende, Belgium.
Each year about 400 regattas, or competitions, are held in the United States and Canada under the auspices of the APBA. The most famous American race is the annual Gold Cup competition, which dates from 1904. It is open to boats of unlimited horsepower with hulls between 28 and 40 feet in length.
Other notable American races include the President's Cup, the Indiana Governor's Cup and the Seafair Trophy.
Important races held elsewhere in the world are the Cowes Torquay in England and the Viareggio Bastia in Italy.