A trimmable rudder system for a marine vessel such as a planing power boat, the system including a pair of rudder assemblies, each of which includes a rudder blade movably coupled to the hull by way of a ball-and-socket joint. Each rudder assembly includes a rudder shaft that extends from the rudder blade through the ball-and-socket joint and can be rotated for rotating the rudder blade to steer the power boat. Each rudder shaft may be operably coupled to a pair of actuators configured to control trim and camber positions of the rudder blade so that the pair of rudder blades can collectively achieve a desired hull trim change, including listing control and planing control of the power boat. Steering position, trim position, and camber position of the rudder blades may be simultaneously changed.

The present invention discloses a tail rudder control device and a kayak. The tail rudder control device comprises a tail rudder assembly. The tail rudder assembly comprises a tail rudder, a swing mechanism, a traction mechanism and a guide wheel box. The traction mechanism comprises a steering bracket in transmission connection with the swing mechanism and the tail rudder; a rotating shaft in transmission connection with the tail rudder to convert circumferential rotation of the rotating shaft into longitudinal flipping of the tail rudder; a first transmission wheel disposed around the rotating shaft and in transmission connection with a guide wheel set in the guide wheel box; and a second transmission wheel disposed around the rotating shaft, capable of moving axially along the rotating shaft, and having a first motion state where the second transmission wheel rotates with respect to the first transmission wheel, a second motion state where the second transmission wheel rotates synchronously with the first transmission wheel and the rotating shaft, and a third motion state where the second transmission wheel rotates synchronously with the steering bracket and the rotating shaft. The technical solution provided by the present invention effectively achieves the purpose of retractably installing the tail rudder on the bottom surface of a boat, effectively avoids collision with the bottom of the boat during the taking-up process of the tail rudder and has a simpler and more reliable overall structure.

According to an aspect of the disclosure, a rudder apparatus for steering a watercraft includes a housing for being coupled to a stern of the watercraft. A blade casing is coupled to the housing. A blade is coupled to the blade casing. The blade casing is pivotally connected to the housing and pivotable with the blade between a deployed position in which the blade extends vertically downwardly into the water, and a stowed position in which the blade extends perpendicularly relative to the deployed position. The blade is pivotable relative to the blade casing from the deployed position to deflected positions to permit the blade to deflect when the blade impacts debris or the bed of the body of water.