Patent ID: 8800459

Claim:
A rudder resistance reducing method, comprising the steps of: a) providing a boat comprising a propeller rotatable to drive said boat to steer and a rudder installed in said boat body at a rear side relative to said propeller; b) installing an air bubble generator in said boat at a front side relative to said rudder, said air bubble generator comprising an air tube arranged to extend externally along a leading edge of said rudder, said air tube having formed therein at least one gas inlet and opposing pairs of gas release outlets communicating with the gas inlet; c) providing a gas guide device comprising at least one guide pipe, said at least one guide pipe having a bottom end thereof connected to said at least one gas inlet of said air tube and a top end thereof terminating in an intake hole; d) employing Bernoulli's principle to produce a negative pressure in said gas release outlets for sucking in outside air for generating air bubbles externally about said rudder during rotation of said propeller to cause a high-speed flow of water externally around said rudder; e) enabling the intake flow of air/gas to be guided by said at least one guide pipe into said at least one gas inlet of said air tube and then discharged out of said gas release outlets to mix with water and to produce multiple air bubbles; and f) utilizing the air bubbles thus produced to displace portions of the high-speed flow of water away from an external surface of said rudder to reduce friction contact between the high-speed flow of water and said rudder and thereby reduce the resistance of said rudder against the high-speed flow of water.