Steering mechanism for a boat having a planing hull
A boat includes a planing hull, a propeller, a main rudder, and a pair of flanking rudders. The planing hull has port and starboard sides, a transom, a hull bottom, and a centerline running down the middle of the boat, halfway between the port and starboard sides. The propeller is positioned forward of the transom and beneath the hull bottom. The main rudder is positioned aft of the propeller. The main rudder has a rotation axis about which the main rudder rotates. The flanking rudders are positioned forward of the propeller. One of the flanking rudders is positioned on the port side of the centerline, and the other flanking rudder is positioned on the starboard side of the centerline.
1. A method of turning a boat having a planing hull, the method comprising:
spinning a propeller in a direction to move the boat in reverse and to accelerate a stream of water;
rotating a port flanking rudder from a first position to a second position about a rotation axis positioned forward of the propeller, the port flanking rudder intersecting the stream of water accelerated by the propeller in the second position, the port flanking rudder being positioned beneath a bottom of a planing hull of the boat and on port side of a centerline of the planing hull;
rotating a starboard flanking rudder from a first position to a second position about a rotation axis positioned forward of the propeller, the starboard flanking rudder intersecting the stream of water accelerated by the propeller in the second position, the starboard flanking rudder being positioned beneath a bottom of a planing hull of the boat and on starboard side of a centerline of the planing hull.
2. The method of claim 1 , wherein the first position of each of the port and starboard flanking rudders is a neutral position.
3. The method of claim 1 , wherein the port flanking rudder is rotated from the first position to the second position by rotating the aft edge of the port flanking rudder in a port direction about the rotation axis of the port flanking rudder, and
wherein the starboard flanking rudder is rotated from the first position to the second position by rotating the aft edge of the starboard flanking rudder in port direction about the rotation axis of the starboard flanking rudder.
4. The method of claim 3 , wherein the first position of each of the port and starboard flanking rudders is a neutral position and the boat is turned to port by rotating the aft edge of each of the port and starboard flanking rudders to port.
5. The method of claim 1 , wherein the port flanking rudder is rotated from the first position to the second position by rotating the aft edge of the port flanking rudder in a starboard direction about the rotation axis of the port flanking rudder, and
wherein the starboard flanking rudder is rotated from the first position to the second position by rotating the aft edge of the starboard flanking rudder in starboard direction about the rotation axis of the starboard flanking rudder.
6. The method of claim 5 , wherein the first position of each of the port and starboard flanking rudders is a neutral position and the boat is turned to starboard by rotating the aft edge of each of the port and starboard flanking rudders to starboard.
7. The method of claim 1 , wherein:
positioning the port flanking rudder in the second position forms a rotation angle between the chord of the port flanking rudder and a line that is (i) parallel to the centerline of the boat and (ii) intersects the rotation axis of the port flanking rudder,
positioning the starboard flanking rudder in the second position forms a rotation angle between the chord of the starboard flanking rudder and a line that is (i) parallel to the centerline of the boat and (ii) intersects the rotation axis of the starboard flanking rudder.
8. The method of claim 7 , wherein, in the second position, the rotation angle of the port flanking rudder is larger than the rotation angle of the starboard flanking rudder.
9. The method of claim 7 , wherein, in the second position, the rotation angle of the starboard flanking rudder is larger than the rotation angle of the port flanking rudder.
10. The method of claim 7 , wherein, in the second position, the rotation angle of the starboard flanking rudder is the same as the rotation angle of the port flanking rudder.
11. The method of claim 1 , wherein the port flanking rudder is rotated from the first position to the second position at a rotation rate, and
wherein the starboard flanking rudder is rotated from the first position to the second position at a rotation rate.
12. The method of claim 11 , wherein the rotation rate of the port flanking rudder is faster than the rotation rate of the starboard flanking rudder.
13. The method of claim 11 , wherein the rotation rate of the starboard flanking rudder is faster than the rotation rate of the port flanking rudder.
14. The method of claim 11 , wherein the rotation rate of the port flanking rudder is the same as the rotation rate of the starboard flanking rudder.
15. A method of turning a boat having a planing hull, the method comprising:
spinning a propeller in a direction to move the boat in reverse, the propeller having a diameter;
rotating a port flanking rudder from a first position to a second position about a rotation axis positioned (i) forward of the propeller and (ii) laterally within the diameter of the propeller, the port flanking rudder being positioned beneath a bottom of a planing hull of the boat and on port side of a centerline of the planing hull;
rotating a starboard flanking rudder from a first position to a second position about a rotation axis positioned (i) forward of the propeller and (ii) laterally within the diameter of the propeller, the starboard flanking rudder being positioned beneath a bottom of a planing hull of the boat and on starboard side of a centerline of the planing hull.
16. The method of claim 15 , wherein the rotation axis of each of the port flanking rudder and the starboard flanking rudder is positioned forward of the propeller a distance that is less than or equal to three times the propeller diameter.
17. The method of claim 15 , wherein the port flanking rudder is rotated from the first position to the second position by rotating the aft edge of the port flanking rudder in a port direction about the rotation axis of the port flanking rudder, and
wherein the starboard flanking rudder is rotated from the first position to the second position by rotating the aft edge of the starboard flanking rudder in port direction about the rotation axis of the starboard flanking rudder.
18. The method of claim 17 , wherein the first position of each of the port and starboard flanking rudders is a neutral position and the boat is turned to port by rotating the aft edge of each of the port and starboard flanking rudders to port.
19. The method of claim 15 , wherein the port flanking rudder is rotated from the first position to the second position by rotating the aft edge of the port flanking rudder in a starboard direction about the rotation axis of the port flanking rudder, and
wherein the starboard flanking rudder is rotated from the first position to the second position by rotating the aft edge of the starboard flanking rudder in starboard direction about the rotation axis of the starboard flanking rudder.
20. The method of claim 19 , wherein the first position of each of the port and starboard flanking rudders is a neutral position and the boat is turned to starboard by rotating the aft edge of each of the port and starboard flanking rudders to starboard.