A system for retracting a foil of a watercraft in the event of an impact has a strut extending from a watercraft, the strut has a pivot at one end that connects the strut to the watercraft and allows the strut to articulate around the pivot, a foil attached at a second end of the strut, wherein the foil has sufficient surface area configured to generate positive lift when the watercraft is traveling over water; and a retraction system including a mechanical fuse connected to the strut, the mechanical fuse holds the strut stationary and is subject to forces from the strut when the strut travels through water, the retraction system allows retraction of the strut around the pivot when the strut experiences a force greater than a predetermined limit, and the foil is configured to articulate on the strut to maintain positive lift orientation as the strut is retracting.

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 system for retracting a foil of a watercraft in the event of an impact has a strut extending from a watercraft, the strut has a pivot at one end that connects the strut to the watercraft and allows the strut to articulate around the pivot, a foil attached at a second end of the strut, wherein the foil has sufficient surface area configured to generate positive lift when the watercraft is traveling over water; and a retraction system including a mechanical fuse connected to the strut, the mechanical fuse holds the strut stationary and is subject to forces from the strut when the strut travels through water, the retraction system allows retraction of the strut around the pivot when the strut experiences a force greater than a predetermined limit, and the foil is configured to articulate on the strut to maintain positive lift orientation as the strut is retracting.

A foil displacement system includes one or more foils that can be deployed and stowed. When deployed, each foil can exert downforce or uplift depending on its orientation. For example, each foil may be positioned to have an angle of attack that creates a downward force effectively transmitted to the hull to pull the hull deeper within the water to, for example, create a larger wake. Use of the foil displacement system can enhance or replace the use of a ballast tank system, can be integrated into a new boat or retrofitted to existing boats, can be electronically or manually positioned, can enhance activities such as wake surfing, wake boarding, water skiing or other similar or related water sports.

A foil displacement system includes one or more foils that can be deployed and stowed. When deployed, each foil can exert downforce or uplift depending on its orientation. For example, each foil may be positioned to have an angle of attack that creates a downward force effectively transmitted to the hull to pull the hull deeper within the water to, for example, create a larger wake. Use of the foil displacement system can enhance or replace the use of a ballast tank system, can be integrated into a new boat or retrofitted to existing boats, can be electronically or manually positioned, can enhance activities such as wake surfing, wake boarding, water skiing or other similar or related water sports.

A hydrofoil craft includes a hull including a bottom that spreads from a bow to a stern; and a hydrofoil mechanism provided on the bow side of the hull. The hull further includes an accommodating recess formed therein, and the accommodating recess is recessed toward the stern side between the bow and the bottom to accommodate the hydrofoil mechanism. A retreat surface is formed between the bottom and a recess main surface facing the bow side in the accommodating recess, and the retreat surface extends toward the stern side in a downward direction and is connected to the bottom.

Safety strut assembly (9) for a hydrofoil craft (1) comprising a strut (12), which is attached to the hull (10) of the craft by means of a transverse oriented strut axle (40) for pivotal movement with respect to the hull, the assembly further comprising: a control rod (33) passing down through the strut (12); a linear actuator assembly (28); a hydrofoil (13) pivotally mounted to the bottom portion of the strut (12) about a transverse oriented foil axle (35); first linkage means (34) connecting the hydrofoil (13) to the control rod (33); wherein the first linkage means (34) comprises a first drive ring (48) mounted around the foil axle (35), wherein the first drive ring is provided with one first ring cam element (45), and wherein the foil axle (35) is provided with one foil axle cam element (46).

A foil displacement system includes one or more foils that can be deployed and stowed. When deployed, each foil can exert downforce or uplift depending on its orientation. For example, each foil may be positioned to have an angle of attack that creates a downward force effectively transmitted to the hull to pull the hull deeper within the water to, for example, create a larger wake. Use of the foil displacement system can enhance or replace the use of a ballast tank system, can be integrated into a new boat or retrofitted to existing boats, can be electronically or manually positioned, can enhance activities such as wake surfing, wake boarding, water skiing or other similar or related water sports.

A hydrofoil craft includes: a hull including a bottom that spreads from a bow to a stern; and a hydrofoil mechanism provided on the bow side of the hull. The hull includes an accommodating recess formed therein, the accommodating recess being recessed toward the stern side between the bow and the bottom to accommodate the hydrofoil mechanism. A retreat surface is formed between the bottom and a recess main surface facing the bow side in the accommodating recess, the retreat surface extending toward the stern side in a downward direction and being connected to the bottom.