Monday, April 02, 2007

Air boats

Air boats, is also known as fan boats, and are flat-bottomed punts motorized by a propeller attached to an automobile or aircraft engine. The propeller has the typical shape and size of an airplane propeller and so requires a large metal cage to look after passengers and other users. The flat bottom allows air boats to find the way easily through shallow swamps and marshes as well as in canals, rivers and lakes; it can also be used on frozen lakes. The driver sits high on a platform to recover visibility and to permit spotting floating obstacles and animals in the alleyway of the boat. Steering is expert by swiveling vertical fins positioned in the propeller wash in the very rear of the airboat, so control is a function of current, wind, water depth and propeller thrust. Crabbing into the wind or current is necessary. The noise from the propeller and engine is quite loud; the greater part of the noise is produced by the propeller. Air boats vary in size from 18 person tour boats to trail boats accepted on a road trailer and suitable for two or three passengers.