Abstract: Protective caps for the ends of sailboat spreaders comprise an arcuate outer surface over which a sail or line may pass without being snagged, an opening sized to snugly fit over the end of the spreader, a slot arrangement to permit the cap to fit over a shroud that runs through the end of the spreader and bores in the cap normal to the slot arrangement into which a cotter pin may be inserted to hold the cap onto the spreader end.

Abstract: A sailing ship (1) has at least one mast (2,3,4) rigidly attached thereto, to which the yards (5 to 9) are rotatably attached. By an actuating shaft (21), the sail (22, 22a, 22b) can be reefed and, with the aid of a corresponding rope (24), it can be erected or stretched. The sail (22, 22a, 22b) is narrower in the middle than at the edges and has upper and lower boltropes (48, 49) that are guided in grooves (27) to the yards (5-9). Erecting and reefing of the sail (22, 22a, 22b) and bracing can be accomplished by remote control. Because of the high speed that can be attained, energy recovery is possible with a propeller.

Abstract: There is described an extendable telescoping pole which can be locked in an extended position. The pole includes a rope or line which can be manually adjusted to thereby continuously adjust the length of the pole. The line can be locked in position to assure that the pole remains at the appropriate extended length.

Abstract: A collapsible wind propelled watercraft adapted for movement over water having a substantially tetrahedral frame comprising three substantially equidistantly spaced support members adapted to engage and be supported on the surface of the water, four substantially rigid spars hingedly connected together at a juncture and extending radially outwardly therefrom such that three of the spars may articulate about the fourth spar to collapse the frame, the four spars further being separated from each other by equal angles. A plurality of stays are connected between each one of the spars and the other spars at points on the spars substantially equidistant from the juncture so as to form the substantially tetrahedral frame, and three of the spars extend laterally and downwardly from the juncture and have the support members connected near their distal ends. Suspended in the area defined by the three spars and the water surface is a trampoline connected to the distal ends of the three spars extending downwardly.

Abstract: A rotatable spar apparatus for controlling and adjusting sail shape which includes a curved, rigid spar which is arranged to reverse its curvature when tacking. Additionally by controlling the degree of rotation it may be used as a draft control device.

Abstract: A spinnaker boom hingedly attached to the mast of a sailing boat by a traveller. The traveller is movable along the boom so that the boom can be moved relative to the mast substantially transversely to the longitudinal direction of the boat.

Abstract: A radar loaded, hollow yacht mast is disclosed which is pivoted at the bottom to the deck by a tri-sectioned elastomeric torsion spring hinge assembly in which the torsion is produced by relative rotation between the inner section and the two outer sections. The torsional resistance of the hinge assembly prevents the mast from falling when the bolts and stays are removed and the restoring force in the spring elastomer when the mast is pivoted flat to the deck assists in raising the mast back into its upright position. A hollow, flanged mounting connecting the hollow mast to the movable section of the hinge assembly prevents sea water from entering the hollows. Provisions are provided for pre-loading the hinge spring with a torsional stress in either direction when the hinge is closed.

Abstract: A configuration for a sailboat mainsail comprises a rotating wind-mill like sail structure mounted on a rotating pedestal base. The wind driven rotating sail delivers power to the sailboat propeller through a flexible driveshaft and transmission and thus provides an ability to sail a particular desired course direction irrespective of the direction from which the wind is blowing.

Abstract: A wind propelled craft adapted for movement over water or ice having an equilateral tetrahedral frame comprising three substantially equidistantly spaced support members adapted to engage and be supported on the surface of the water, four substantially rigid spars connected together at a juncture and extending radially outward therefrom such that they are separated from each other by equal angles, and a plurality of equilength stays connected between each of the spars and the other spars at points on the spars substantially equidistant from the juncture so as to form with the spars a frame of substantially equilateral tetrahedral shape. Three of the spars extend laterally and downwardly from the juncture and are connected to the support members by stays with the fourth spar extending upwardly from the juncture. A pair of triangular mainsails are connected to respective pairs of stays extending downwardly from the vertical spar in such a manner that they are capable of being raised and lowered.