A sail furler for a sail boat and method for furling a sail for reefing or storage and for unfurling a sail for use. Furling and unfurling of the sail may be accomplished from the cockpit of the sailboat. A mandrel is mounted to the mast extending generally parallel to the boom and attached to the aft end of boom by an aft plate. The mandrel is mounted in bearings and provided with a removable crank for rotation. The mandrel is connected to the mast by a universal joint and bearing structure over which is provided an outer cylinder. A cylinder and resilient sleeve may be provided on the mandrel. A reef brake extends from the mandrel into contact with the boom to prevent rotation for reefing the sail. A slide guard may be mounted at the mast end of the mandrel.

The present invention relates to a water-air interface vehicle suitable for concealed navigation. A gybing box is arranged in a hull and includes a gybing motor, a gear train, a worm wheel and worm mechanism and a base; the worm wheel and worm mechanism is connected with a shaft of the gybing motor by the gear train; the base is connected with the worm wheel and worm mechanism; the transformable sail is fixed to the base; the gybing box is connected with a reefing mechanism; the gybing box operates the transformable sail in a set attack angle range or rotates 90 degrees under the action of the reefing mechanism according to a signal sent by a control system.

A water-air interface vehicle suitable for concealed navigation. A gybing box is arranged in a hull and includes a gybing motor, a gear train, a worm wheel and worm mechanism and a base; the worm wheel and worm mechanism are connected with a shaft of the gybing motor by the gear train; the base is connected with the worm wheel and worm mechanism; the transformable sail is fixed to the base; the gybing box is connected with a reefing mechanism; the gybing box operates the transformable sail in a set attack angle range or rotates 90 degrees according to a signal sent by a control system.