Sailboat keel apparatus

In a boat, attitude control apparatus comprising:

• a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, a keel means pendant from said keel axis for angulation about said keel axis;
• said keel means having port and starboard facing sides, port and starboard facing shock absorber means comprising port and starboard facing tracks respectively in the port and starboard facing sides of said keel means, said tracks being directed radially from said keel axis, and port and starboard facing sliders captured respectively in said port and starboard facing tracks, said tracks and sliders being configured to cooperate with ambient water about said keel means, to produce viscous frictional forces opposing movement of said sliders along said tracks;
• arising from ambient water displaced by the movement of said sliders being forced through relatively narrow openings in said tracks;
• and port and starboard actuators respectively connected to said port and starboard facing sliders for positioning said keel means angularly about said keel axis.

In a boat, attitude control apparatus comprising:

• a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat;
• a keel means, comprising angularly opposed independently positionable port and starboard keel sections, pendant from said keel axis for angulation about said keel axis;
• port and starboard keel section positioning actuators respectively coupled to said port and starboard keel sections for independently angularly positioning said port and starboard keel sections about said keel axis, said port and starboard keel sections positioning actuators respectively comprising opposed port and starboard hydraulic slave cylinders;
• said apparatus further comprising port and starboard hydraulic master cylinders within said boat respectively hydraulically coupled to said port and starboard slave cylinders, each of said master cylinders having a piston, and control means coupled between the pistons of said port and starboard master cylinders for selectively simultaneously increasing the hydraulic volume of a selected one of said master cylinders and decreasing the hydraulic volume of the other of said master cylinders, for selectively causing said port and starboard keel sections to rotate in the same direction, and hydraulic means coupled hydraulically to each of said master cylinders for selectively causing said port and starboard keel sections to rotate angularly in opposite directions.

In a boat, attitude control apparatus comprising:

• a generally longitudinally directed keel axis mounted at a medial point on the underside of said boat, port and starboard facing angularly opposed keel sections mounted for independent angular positioning about said keel axis;
• port and starboard keel section positioning actuators respectively coupled to said port and starboard facing keel sections for angularly positioning said keel sections about said keel axis, said port and starboard keel section positioning actuators comprising cylinders for receiving opposed hydraulic and air pressures, said cylinders being directed for angularly downwardly rotating said keel sections in response to an excess of hydraulic pressure with respect to air pressure and angularly upwardly rotating said keel sections in response to an excess of air pressure with respect to hydraulic pressure;
• control means within said boat coupled for applying selected hydraulic pressures to said cylinders and air pressure storage tank means within said boat coupled for applying air pressure to said cylinders;
• whereby said keel sections may be raised in opposite directions by air pressure from said storage tanks upon the application of no or relatively small hydraulic pressure from said control means.