Control system for a hydrofoil watercraft with fully submerged hydrofoil

A method of stabilizing a hydrofoil watercraft comprising steps of:

• a. providing a hydrofoil watercraft comprising:
• i. a water-craft base member having a bottom side;
• ii. a hydrofoil mast having proximal and distal portions, said proximal portion mechanically connected to said bottom side of said water-craft base member;
• iii. a fuselage having a main wing, said fuselage mechanically connected to said distal portion of said at least one hydrofoil mast;
• iv. a rudder configured for controlling a yaw angle of said water craft wherein said rudder is connected to an aft portion of said fuselage;
• v. a elevator configured for controlling a pitch angle of said water craft;
• and
• vi. a stabilization arrangement comprising at least one sensor configured for detecting a 3D orientation of said water-craft base member, an estimator configured for estimating a height of said water-craft base member over a water level and yaw, pitch and roll angles, actuators configured for manipulating said rudder and elevator, and a controller implemented within a control unit, said controller configured for analyzing estimated values of the height, yaw, pitch and roll angles and controlling said actuators;
• in response to a disturb roll inclination of said water craft from a predetermined setpoint, said controller is configured for generating a command to a rudder actuator for rotation of said rudder;
• b. sensing and estimating said disturb roll inclination
• c. generating a command by said controller;
• d. transmitting said command to said rudder actuator;
• rotating said rudder by said rudder actuator such that said rudder induces a correcting roll inclination compensating said disturb roll inclination of water craft.