Abstract: For eliminating the dynamic drag of the member which supports the ballast by completely enveloping it with a indispensable component of the sailing vessel, namely, the hollow rotatable monolithic rigid hydrodynamic fin, and thereby reducing the dynamic drag of the canoe body when it is sailing. The elongated four-sided symmetrical diamond shaped ballast support is adapted to be fixed to the interior of the canoe body. The top of the rotatable fin enters into the interior of the canoe body so that the water turbulence is substantially less than in the prior art when the top of the rotatable fin is spaced from the bottom of the canoe body. With sliding convex/concave contact, the rotatable fin is laterally supported by the stationary diamond shaped member. A first and second cylinder are fixed to the canoe body sole and canoe body cabin top to provide strong support to the rotatable fin and ballast.

Abstract: For reducing drag, the velocity of a tacking sailing vessel is increased by isolating the supporting member of the ballast bulb from the sea stream by a jacketing hollow rotatable fin.

Abstract: An asymmetric wing for decreasing the leeward drift of a vessel has two different surfaces, one of which is cambered in cross-section and the other which has less camber in cross-section or flat. The asymmetric wing has a leading edge pointed toward the bow of the vessel and the trailing edge pointed toward the stern of the vessel. The surfaces of the asymmetric wing can be selectively moved to the port or starboard sides of the vessel. For centerboard and sliding keel vessels, a pair of asymmetric wings are installed in trunks, each asymmetric wing having a first cambered surface and a second less cambered surface. The first cambered surfaces of the two asymmetric wings point in opposite directions. At any one time both asymmetric wings are not moved into the water. The asymmetric wing is applicable to vessels without a centerboard or sliding keel trunk. In such a case, a horizontal shaft extends through a single asymmetric wing and the single cambered surface is rotated to either port or starboard.