An underwater recreation system for diving instruction and method of its use. The method includes providing a series of learning steps with diving techniques and instructions to practice at incrementally deeper depths and providing a surface floating depth limitation device that restricts the learning user to the particular maximum depth of their learning step. The apparatus for carrying out the method of diving instruction includes a surface floating depth limitation device with the means to connect to the breathing hose of a surface supplied air supply.

The present invention belongs to the field of equipment for living or working underwater, more precisely to the field of diving equipment, especially underwater propulsion vehicles for divers. The object of the invention is an underwater scooter for divers. The essence of the underwater scooter for divers is in that the thruster is placed above the scuba diving tank when used and below it when it is not used. The interchangeable battery pack is placed around the scuba dive tank. The thruster rotation between both positions is enabled by contact hinge which connects the thruster and the interchangeable battery pack. By holding the command joystick in his/her hand the diver is managing the device. There is a safety cord with karabiner snap hook attached to the command joystick which could be attached to the scuba diving inflated life jacket. Thus, the diver is able to steer the device hands-free.

An underwater motive device includes a rear main housing including two side handle bars, a forward joining member having a decreased diameter, a shoulder between the forward joining member and a remaining portion of the rear main housing, a battery compartment defined in both the forward joining member and the remaining portion of the rear main housing wherein the forward joining member includes an annular front end, an annular front surface between the annular front end and the shoulder, two opposite first rails on a joining portion of the annular front end and the annular front surface, and a first space on the annular front surface and abutting each first rail; and a front cone including a rear opening, an internal, annular surface on a rear portion, and two opposite sets of a second rail and a second space.

A system, methods and apparatus for powered monofin that propels a swimmer through water uses one of two modes of power: 1. An electric-assist mode, in which the propulsor responds to a swimmer's kick by multiplying the work of the swimmer; 2. Inverse mode, in which the propulsor deactivates when the swimmer is working. In this mode, propulsion is inversely related to the work of the swimmer. As the swimmer does more work, power from the monofin is reduced, to a predetermined, average level of propulsion. As the swimmer does less work propulsion increases to the predetermined level.

An underwater motive device includes a rear main housing including two opposite handle bar elements on two sides respectively, and longitudinal rear joining projections on an inner surface; a power mechanism in the rear main housing; a propeller driven by a driving shaft of the power mechanism; a bridging housing including a battery compartment, a forward joining member, a shoulder abutted the forward joining member, and a rear joining member; a hollow intermediate housing including two opposite handle bar members on two sides respectively, the handle bar members joined the handle bar elements, longitudinal front joining projections on an inner surface, and an internal annular limit element at a front end; and a front cone including a rear opening and a structure on an inner surface for securing to the forward joining member of the bridging housing.

Structural arrangement for a water ski or underwater ski comprising essential mechanisms for significantly improving the user experience in underwater wake bodyboarding. The ski is characterized by the addition of novel and different attachable items that enable the ski to be used without a powered vehicle. The ski is also characterized in that it has various different items that can be attached to the cowling to improve the performance and comfort of the equipment, combined with a personalized steering system and an essential safety system, providing a model that is unique on the underwater ski/water ski market.

A low emission submersible engine is part of a multipurpose aquatic device, such as an aquatic craft or an electrical generator. A propulsion system having a propeller is coupled to the submersible engine to produce a swimmer propulsion machine and a generator is attached to the engine to produce an electrical generator. The submersible engine receives air from a snorkel that extends up above a water line The aquatic device has a fuel reservoir which may receive liquid fuel or may receive a fuel cylinder. Floatation chambers keep the aquatic device afloat with the engine submerged. The exhaust assembly and exhaust ports from the engine may also be submerged and the exhaust ports may provide additional thrust. A propulsion system housing integrates the drive shaft and propeller, clutch coupler, exhaust conduits and water flow conduits and is detachably attachable to the engine.

A low emission submersible engine is part of a multipurpose aquatic device, such as an aquatic craft or an electrical generator. A propulsion system having a propeller is coupled to the submersible engine to produce a swimmer propulsion machine and a generator is attached to the engine to produce an electrical generator. The submersible engine receives air from a snorkel that extends up above a water line. The aquatic device has a fuel reservoir which may receive liquid fuel or may receive a fuel cylinder. Floatation chambers keep the aquatic device afloat with the engine submerged. The exhaust assembly and exhaust ports from the engine may also be submerged and the exhaust ports may provide additional thrust. A propulsion system housing integrates the drive shaft and propeller, clutch coupler, exhaust conduits and water flow conduits and is detachably attachable to the engine.

Structural arrangement for a water ski or underwater ski comprising essential mechanisms for significantly improving the user experience in underwater wake bodyboarding. The ski is characterized by the addition of novel and different attachable items that enable the ski to be used without a powered vehicle. The ski is also characterized in that it has various different items that can be attached to the cowling to improve the performance and comfort of the equipment, combined with a personalized steering system and an essential safety system, providing a model that is unique on the underwater ski/water ski market.

A system, methods and apparatus for powered monofin that propels a swimmer through water uses one of two modes of power: 1. An electric-assist mode, in which the propulsor responds to a swimmer's kick by multiplying the work of the swimmer; 2. Inverse mode, in which the propulsor deactivates when the swimmer is working. In this mode, propulsion is inversely related to the work of the swimmer. As the swimmer does more work, power from the monofin is reduced, to a predetermined, average level of propulsion. As the swimmer does less work propulsion increases to the predetermined level.