A sea scooter has a main housing, a left arm pivotably attached to the left side of the main housing, a right arm pivotably attached to the right side of the main housing, a left barrel secured to the left arm, and a right barrel secured to the right arm. Each barrel has a fan and a motor for propelling the sea scooter through water. The left and right arms are locked by the first and second locking assemblies into a folded configuration against the left and right sides of the main housing when the sea scooter is not in use, and the left and right arms are pivoted away from the left and right sides of the main housing in a use configuration when the sea scooter is in use in the water. The motor is sand-proof and water-proof.

A Hybrid Vessel Propulsion and Generation System diesel jet drive outboard and inboard motors, with an electrical generator attached to a prop shaft of the motors to generate electricity to power batteries. On large boats or ships with a gear change, the generator is mounted on the back of the gearbox and is attached to the prop shaft, with the generator being driven by rotation of the prop shaft and the drive of the gearbox. The system also incorporates electrically powered water thrusters and mechanical pressurised water turbines used for charging the batteries. The system also incorporates electric motors attached to propellers powered by electric batteries. Solar panels may be arranged in the port hole windows incorporating a housing, latch and lever arms to position them towards the sun.

A ship screw, pump screw or turbine screw for use under water or another liquid, comprising a front side and a rear side, wherein water or another liquid is forced from the front side to the rear side in use, and comprising a hub and at least two blades extending from said hub, wherein the blades are substantially helical/spiral shaped, their effective surface area increasing from the front side toward the rear side.

A ship screw, pump screw or turbine screw for use under water or another liquid, comprising a front side and a rear side, wherein water or another liquid is forced from the front side to the rear side in use, and comprising a hub and at least two blades extending from said hub, wherein the blades are substantially helical/spiral shaped, their effective surface area increasing from the front side toward the rear side.

An impeller includes a hub, and a plurality of blades supported by the hub, the blades being arranged in at least two blade rows. The impeller has a deployed configuration in which the blades extend away from the hub, and a stored configuration in which at least one of the blades is radially compressed, for example by folding the blade towards the hub. The impeller may also have an operational configuration in which at least some of the blades are deformed from the deployed configuration upon rotation of the impeller when in the deployed configuration. The outer edge of one or more blades may have a winglet, and the base of the blades may have an associated indentation to facilitate folding of the blades.

A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which an intake mount is secured. The jet drive is supported by the intake mount. The shield has at least one flange adapted to be secured to a middle toon of a pontoon boat. The shield covers an opening in the middle toon through which the marine engine is passed during assembly. A gasket between the shield and opening prevents water from entering the middle toon.

A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which an intake mount is secured. The jet drive is supported by the intake mount. The shield has at least one flange adapted to be secured to a middle toon of a pontoon boat. The shield covers an opening in the middle toon through which the marine engine is passed during assembly. A gasket between the shield and opening prevents water from entering the middle toon.

A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which the jet drive is secured, the arms and legs extending in opposite directions. The shield has a flange adapted to be secured to the transom of the watercraft. The shield covers an opening in the transom through which the jet pump assembly is passed during assembly. A gasket between the shield and transom prevents water from entering the watercraft.

A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which the jet drive is secured, the arms and legs extending in opposite directions. The shield has a flange adapted to be secured to the transom of the watercraft. The shield covers an opening in the transom through which the jet pump assembly is passed during assembly. A gasket between the shield and transom prevents water from entering the watercraft.

An underwater propulsion apparatus 1 according to an embodiment includes a main body 2 having a conical tail portion, a channel 4 having an inlet 6 in the outer circumferential surface of the main body 2 and a nozzle 7 on the side downstream of the inlet 6 and in the tail portion, at least one pump 3 having an impeller 5 provided in the channel 4, a diffuser 8 attached to the main body 2 so as to surround the outer circumference of the nozzle 7, and a plurality of direction control wings 9 attached to the outer surface of the main body 2 and located in positions downstream of the nozzle 7 and close thereto, each of the plurality of direction control wings 9 having an upstream end pivotally supported by the main body 2.