Abstract: A carbon fiber spar is provided which comprises a layer of carbon fiber forming a one-piece circumference and having an integral sail-attaching groove formed by a plastic insert bonded together with the layer of carbon fiber during curing so that the fiber layer forms a hollow for receiving the plastic insert in interlocking engagement.

Abstract: A spar is provided comprising an inner layer of fiber, an outer layer of fiber, a hollow between the inner and outer layers of fiber with the inner fiber layer forming a surface of the hollow such that it is integral in one piece with the spar. The spar preferably includes a cut through the outer fiber layer into the hollow to form a groove for attaching a sail. The invention also provides a method of making spars including the steps of forming a first layer, pressing the layer inwardly along a line to form a groove, applying a second layer over the first, and combining the layers together except along the line. The method preferably also includes the step of cutting through the second layer along the line into the groove.

Abstract: Apparatus for reefing sails on a boat and specially-designed boom including such an apparatus. The hollow boom extrusion houses at least one traveler block with two pulley wheels, over which pass the reefing leech line and the reefing luff line. The apparatus makes it possible to take one or more reefs in the sail simply by pulling on the free end of the reefing luff line which leads to the cockpit of the boat.

Abstract: A mast of simplified and standardized constructional design consists of a tubular section and ancillary components such as a masthead or boom support plates which are welded to the tubular section, the masthead being constituted by a casing and head-piece. The casing is provided with an incorporated anchoring member for the standing rigging, and with slots for receiving the axle-pins of sheaves and rollers. The casign head-piece has a central cheek for locking the sheave pins in position.

Abstract: The device comprises an element for rigidly fixing the articulated coupling device to a mast and a boom end-piece which are capable of pivotal displacement in perpendicular planes and each mounted on a common nut by means of a fork. Ribs and grooves formed respectively on the fork and in the nut remain in a position of interengagement after relative rotation through an angle of approximately 180.degree. with respect to a position of introduction of the fork into the nut.The invention is primarily applicable to the boom of a sailing boat which is pivotally coupled to a mast.