The invention relates to an accumulator module (26) comprising a moisture-proof housing (28), in which a plurality of accumulator cells (31) is disposed, the contacts of which are electrically interconnected and which are routed to external contacts (30) of the accumulator module (26) disposed at the outer face of the housing (28). To be able to detect a short circuit between the external contacts (30) of the accumulator module (26) in the simplest and most efficient manner possible, it is proposed that a protection device (35) is disposed inside the housing (28), which protection device comprises a detection device (36), which is designed to detect a short circuit between the external contacts (30). Furthermore, the invention relates to a swimming and diving aid (10) comprising such an accumulator module (26).

A novel watercraft propulsion device is disclosed that includes multiple propulsive elements improving power and efficiency over prior designs. A self-adjusting variable pitch propeller is combined with a water jet and an exhaust driven turbine to provide optimal thrust and efficiency across the range of engine power, load and watercraft speed. Propulsive elements are axially disposed around a central drive shaft and exhaust port with the combined water jet/exhaust turbine disposed closest to drive shaft and the variable pitch propeller attached to the exterior of the water jet housing. A rotating duct is fixed to the propeller blades and rotates with the blades to reduce cavitation. Combined apparatus provides increased performance and efficiency over all watercraft speeds/load as well as additional safety due to the ducted propeller. Propulsor with an inducer, conical impeller and a diffuser also shown.

A planing boat including: a hull having a boarding area; a screw unit having a screw, and configured to be rotatable with respect to the hull so that the expulsion direction of a water current by the screw can vary by 360 degrees; and a direction change mechanism having a turning drive force source, and configured to change the expulsion direction by rotating the screw unit with respect to the hull with a drive force of the turning drive force source.

The invention relates to a surfboard with an electric drive (2), a battery for the electric drive (2), said battery being arranged in a battery housing (3), a first recess (4) for the battery housing (3), and a handle (5) on the battery housing (3), wherein the handle (5) is designed as a D-shaped bracket handle which is pivotally mounted on opposite sides (6) of the battery housing (3) and has a locking mechanism (7) for the first recess (4).

A surfboard with an electric drive (2), a battery for the electric drive (2), said battery being arranged in a battery housing (3), a first recess (4) for the battery housing (3), and a handle (5) on the battery housing (3), wherein the handle (5) is designed as a bracket handle which is mounted pivotably around a respective centre of rotation (21) at each of the handle ends on opposite sides (6) of the battery housing (3), and in each case a lug (9) protrudes from the base side of the recess below the centres of rotation (21) inside the first recess (4), and at each handle end of the bracket handle a second projection (33) is formed, which has a curved edge (34) and which rests on the lug, and a distance between a contact point of the curved edge (34) with the lug (9).

A water sports device is provided which is configured for self-stabilization. The water sports device includes an active stabilization means, in the case of which the control unit provides control signals for actuators of the water sports device, actuators being active adjusting means. These can be a motor of the propulsion apparatus, adjustable flaps or nozzles, or adjustable fins, rudders, hydrofoils or individual adjustable sections thereof. Input data such as data about the position of the water sports device, power output of the propulsion apparatus, speed, acceleration and/or user inputs are evaluated in the control unit, and control commands for an actuator or a plurality of actuators are generated.

A water sports device is provided in which a propulsion device has at least one sensor arrangement which is usable for position determination. A control unit of the water sports device is designed for generating control signals on the basis of signals from the sensor arrangement for the purpose of geofencing and/or homing. One or more controllable elements of the water sports device are activated by means of the control signals. Such elements may include a motor of the propulsion device, movable means for generating an alignment of a water jet (e.g. a wing, motor, rudder blade, a fin and/or nozzle), and/or retractable and extendable elements (a centerboard, a holding and/or hydrofoil device) which influence the floating properties of the water sports device.

A novel watercraft propulsion device is disclosed that includes multiple propulsive elements improving power and efficiency over prior designs. A self-adjusting variable pitch propeller is combined with a water jet and an exhaust driven turbine to provide optimal thrust and efficiency across the range of engine power, load and watercraft speed. In the preferred embodiment, propulsive elements are axially disposed around a central drive shaft and exhaust port with the combined water jet/exhaust turbine disposed closest to drive shaft and the variable pitch propeller attached to the exterior of the water jet housing. A rotating duct is fixed to the propeller blades and rotates with the blades to reduce cavitation. Combined apparatus provides increased performance and efficiency over all watercraft speeds/load as well as additional safety due to the ducted propeller.

A camera produces image data representing an image of a surrounding view of a watercraft. A controller obtains the image data. The controller recognizes an image representing a specific mark in the image data. With reference to a control data set, the controller obtains watercraft operating information associated with the specific mark recognized in the image data. The control data set defines a relationship between the specific mark and the watercraft operating information.

A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is separate from the propulsion system. The propulsion system includes a water intake configured to take in water from a body of water, the water intake including an intake grate and a base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.