A stabilized a hydrofoil water craft comprising: a water-craft base member, a hydrofoil mast having proximal and distal portions; said proximal portion mechanically connected to said bottom side of said water-craft base member, a fuselage mechanically connected to said distal portion of said at least one hydrofoil mast, a rudder configured for controlling a yaw angle of said water craft, an elevator rotatable around an axis lying in a plane parallel to water-craft base member and a stabilization arrangement further comprising at least one sensor configured for detecting a 3D orientation of said water-craft base member, an estimator configured for estimating the 3D orientation, actuators for manipulating the rudder and elevator and a controller for analyzing the estimated 3D orientation and controlling the actuators. In response to a disturb roll inclination of the water craft, the controller generates a command to a rudder actuator to compensate the detected inclination.

A stabilized a hydrofoil water craft comprising: a water-craft base member, a hydrofoil mast having proximal and distal portions; said proximal portion mechanically connected to said bottom side of said water-craft base member, a fuselage mechanically connected to said distal portion of said at least one hydrofoil mast, a rudder configured for controlling a yaw angle of said water craft, an elevator rotatable around an axis lying in a plane parallel to water-craft base member and a stabilization arrangement further comprising at least one sensor configured for detecting a 3D orientation of said water-craft base member, an estimator configured for estimating the 3D orientation, actuators for manipulating the rudder and elevator and a controller for analyzing the estimated 3D orientation and controlling the actuators. In response to a disturb roll inclination of the water craft, the controller generates a command to a rudder actuator to compensate the detected inclination.

An electric hydrofoil board having a submersion-cooled powertrain is provided. A powertrain assembly, which includes a motor housed in a motor assembly and an electronic speed controller housed in a nose cone assembly that is fastened to the motor assembly, is attached to a lower end of a mast of the hydrofoil board so that the powertrain assembly remains submerged at all times during normal use of the hydrofoil board in a body of water. The flow of water around the powertrain assembly during normal use cools heat-generating components of the electronic speed controller and motor.

An electric hydrofoil board having a submersion-cooled powertrain is provided. A powertrain assembly, which includes a motor housed in a motor assembly and an electronic speed controller housed in a nose cone assembly that is fastened to the motor assembly, is attached to a lower end of a mast of the hydrofoil board so that the powertrain assembly remains submerged at all times during normal use of the hydrofoil board in a body of water. The flow of water around the powertrain assembly during normal use cools heat-generating components of the electronic speed controller and motor.

Extended range, removeable batteries, and removeable electronic control modules for a motorized surfboard fin is disclosed. The motorized fin is attached to the bottom of a surfboard to assist a surf rider in paddling, propulsion, and catching a wave. The motorized fin device integrates a propeller, motor, battery, charging assembly, and related electronics, which are activated by the rider via a remote control. The fin is adapted to fit standardized fin securement systems by way of interchangeable connectors. The remote control has geolocation tracking and wireless charging capability. A software application for use with a smartphone is used to perform configuration and maintenance functions.

Extended range, removeable batteries, and removeable electronic control modules for a motorized surfboard fin is disclosed. The motorized fin is attached to the bottom of a surfboard to assist a surf rider in paddling, propulsion, and catching a wave. The motorized fin device integrates a propeller, motor, battery, charging assembly, and related electronics, which are activated by the rider via a remote control. The fin is adapted to fit standardized fin securement systems by way of interchangeable connectors. The remote control has geolocation tracking and wireless charging capability. A software application for use with a smartphone is used to perform configuration and maintenance functions.

A watercraft including: a motor drive; a stern module; a bow module releasably connected to the stern module by a first connector; a controller; and a remote control configured to be operated by an operator. The remote control being configured to transfer movement control signals to the controller for operating the motor drive. Where the stern module having a first receiver, and the bow module having a transmitter. The transmitter is connected to the remote control and is configured to transmit the movement control signals received from the remote control. The first receiver is configured to receive the movement control signals from the first transmitter and forward the movement control signals to the controller.

A watercraft including: a motor drive; a stern module; a bow module releasably connected to the stern module by a first connector; a controller; and a remote control configured to be operated by an operator. The remote control being configured to transfer movement control signals to the controller for operating the motor drive. Where the stern module having a first receiver, and the bow module having a transmitter. The transmitter is connected to the remote control and is configured to transmit the movement control signals received from the remote control. The first receiver is configured to receive the movement control signals from the first transmitter and forward the movement control signals to the controller.

A leash system and methods of use are provided that includes a leash cord configured to be affixed at a first end portion to a user of a personal watercraft, a switch cord, and an anchoring cord. The switch cord has a first end portion affixed to a key for connection to a kill switch of the watercraft and a second end portion affixed to the leash cord. The anchoring cord has a first end portion configured to fixedly secure the anchoring cord to the watercraft and a second end portion affixed to the leash cord. A loop is affixed in preferred examples along the anchoring cord that is configured to slidably receive the switch cord therethrough. When the leash cord is pulled taut while the anchoring cord is fixedly secured to the watercraft, the first end portion of the switch cord is drawn toward the loop to remove the key from the kill switch.

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.