US 7,540,253 B2
	Boat steering system
Makoto Mizutani, Shizuoka-ken (Japan)
Assigned to Yamaha Hatsudoki Kabushiki Kaisha, Shizuoka (Japan)
Filed on Sep. 21, 2007, as Appl. No. 11/859,654.
Claims priority of application No. 2006-312172 (JP), filed on Nov. 17, 2006.
Prior Publication US 2008/0115713 A1, May 22, 2008
Int. Cl. B63H 25/00 (2006.01); B63H 25/06 (2006.01)

U.S. Cl. 114—144RE  [114/162]

16 Claims

1. A boat, comprising a hull, a propulsion unit at a stern of the hull, a steering device comprising a deflectable direction guide member and an electric actuator for deflecting the direction guide member so as to steer the boat, a steering wheel operable by an operator, the steering wheel adapted to provide an actuation signal corresponding to the amount of a steering wheel operation, a controller adapted to receive the steering wheel actuation signal and to direct the electric actuator to deflect the direction guide member, the controller configured to obtain or receive detection data concerning at least one of an operation status corresponding to the steering wheel operation, a running status of the boat, a status of the propulsion unit, and a status of the electric actuator, wherein the controller calculates a direction guide member deflection angle limit based on at least one of the detection data, the direction guide member deflection angle limit being calculated so that direction guide member deflection remains within a range in which the electric actuator maintains a threshold performance level so that steering performance remains advantageous.