Abstract: An adjustable fin apparatus adjustable between a first expanded position including a pair of inner elongated blades 12 and a pair of outer elongated blades 14; the blades 12, 14 are mounted to a blade housing portion 16 comprising an upper housing element 18 and a lower housing element 20; the lower blade housing element 20 comprises an elongate shape having a slot 22 formed therein along a portion of the length of the lower blade housing element 20; the inner elongated blades 12 comprise an inner edge 26 and an outer edge 28 and a bore 30 is located at an end thereof; an outer elongated blade 14 defines an inner edge 32 and an outer edge 34; and the upper blade housing element 18 comprises an elongate shape generally corresponding to the elongate shape of the lower blade housing element 20.

Abstract: A system and method for a motorcycle to automatically variably adjust the wheelbase length including a rear swing arm having a length and a rear wheel attached thereto, a prime mover that generates a motive force for selectably extending or retracting the length of the swing arm to extend or retract the rear wheel, and means for lengthening or retracting a motorcycle driveline providing power to the rear wheels.

Abstract: An adjustable fin apparatus includes an elongated blade portion and elongated first and second frame members adapted for pivotal connection to the blade. An adjustment system for the first and second frame members rotates the pivotal connection of the frame members with respect to the blade. A thin web of a flexible polymeric material extends between the first frame member and the blade portion and between the second frame member and the blade portion.

Abstract: A diving-tank-pocket buoyancy compensator has an expandable diving-tank pocket (1) that envelopes a diving tank (2) which the diving-tank pocket is articulated for containing in addition to at least an inflated buoyancy air cell (3). The buoyancy air cell is in fluid communication with a cell end (4) of a buoyancy compensator (BC) tube (5) which has a tank end (6) in fluid communication with an inside periphery of the diving tank through a regulator tube (35) and a regulator valve (7) on the diving tank. An adjustable pressure valve (8,38) intermediate the tank end and the cell end of the BC tube is provided to maintain a pre-determined pressure and resulting constant volume of air in the buoyancy air cell for maintaining a desired constant buoyancy.

Abstract: The invention comprises a propulsion system attachment for use with a flotation board adapted with a mounting plug. The propulsion system comprises a shell housing which is adapted to be removably attached to a mounting plug member provided on the flotation board, a propeller motor, a power supply for the motor, and a remote control for operating the speed of the motor. The propulsion system also comes equipped with an air bag for maintaining buoyancy to the flotation board and to support the weight of the snorkeler. The air bag is provided with an air line so that the snorkeler can inflate and deflate as necessary to effect the proper buoyancy level. The snorkel board has handles for the user to grasp to aid in maneuvering the board. A supplemental air bag may be disposed underneath the rear of the snorkel board to help provide additional buoyancy to the board in the water.

Abstract: A detachable propulsion unit for a scuba diver's air tank is provided to create a hands-free personal propulsion device. The invention comprises an air tank receiving boot member, a propeller motor, power supply and quick connect straps for attachment to the diver. The unit may be quickly released from the air tank in the event of an emergency. A buoyancy and trim control air bag is also provided to help the diver maintain horizontal trim in the water and to control ballast. If desired, an attachment is provided to allow conversion into a hand held propulsion unit separate from connection with the air tank.