Hydroplane (redirected from Drag boat)

hydroplane, small, high-powered racing boat designed to skim along the surface of the water. Its hull is so shaped that at high speeds the bow is tilted up out of the water, reducing the effect of frictional drag. Hydroplanes are commonly powered by outboard motors.

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hydroplane

1. a motorboat equipped with hydrofoils or with a shaped bottom that raises its hull out of the water at high speeds

2. an attachment to an aircraft to enable it to glide along the surface of water

3. another name (esp US) for a seaplane

4. a horizontal vane on the hull of a submarine for controlling its vertical motion

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hydroplane [′hī·drə‚plān]

(naval architecture)

A boat which when operated at high speed planes on the surface of the water; the bottom of such a craft is normally a prismatic surface. Also known as planing boat.

diving rudder

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Hydroplane 

a light, high-speed vessel. Because of the special shape of its bottom, during mption the hydroplane gains hydrodynamic thrust, which lifts the nose part and causes a significant general up-floating of the vessel. (It appears to slip or glide along the surface of the water.) As a result, the area of contact between the bottom and the water is reduced, resistance to movement decreases, and the traveling speed increases. Light internal combustion engines and gas turbines are mounted on hydroplanes. Propellers (less often, airscrews) and water jets serve as propelling devices. Hydroplanes are used to carry passengers, for guard duty, in sport races, and for pleasure.