Abstract: A marine propulsion unit lower gear housing permits disassembly by rearranging easily removable parts for engagement with non-easily removable parts thereby permitting the use of standard wrenches for disassembly and assembly.

Abstract: A low noise level, rapidly reversible propulsion system for a submarine or other vessel comprises a non-reversible adjustable speed prime mover, a reversible drive mechanism driven by the prime mover and including a fluid-cooled torque converter and speed reduction apparatus, an energy-dissipating load selectively connectable to the reversible drive mechanism, and a propeller driven by the reversible drive mechanism.

Abstract: The invention relates to an accessory for outboard motors, Z-drives for boats or the like, the exhaust gas of which is normally conducted through the propeller hub into the water. By means of a valve system, which is suitably automatically changed over by the direction of rotation of the propeller, the exhaust gas, during rearward rotation of the propeller, is conducted to a region which lies outside the propeller suction, while the exhaust gas, during forward rotation of the propeller, flows out in the usual manner through the propeller hub. The success of the invention lies in a significant increase of the propeller propulsion during rearward travel.

Abstract: A remote controlled self-propelled toy vehicle is disclosed which is capable of moving on a solid support surface and also on water. Two motors and a power source are mounted to the hull of the toy vehicle. Each motor drives, through a suitable transmission assembly, a drive wheel and a screw propeller. The drive wheels are disposed to come into contact with the solid support surface for operation as a land going vehicle, and the screw propellers are disposed for submersion in water when the toy vehicle is operated as a boat.Steering of the vehicle is accomplished on the solid surface and also on water by varying the power output of the motors so that uneven power output of the two motors causes the vehicle to turn. A suitable, preferably radio signal emitting remote control system and associated circuitry is provided to allow a player to steer the vehicle from a remote location.

Abstract: The device comprises an assembly of three principal components, a member for embedding in the rear wall of a tabular iceberg at some depth below the water line, a support structure projecting therefrom and a propulsion unit. It preferably includes a shield to transmit the thrust to a sufficiently large surface of the iceberg wall to avoid creep problems. The propulsion unit may be an electric motor.