A control system for a marine vessel includes an autopilot system and a power steering system. The autopilot system is arranged to receive a first signal indicative of navigation information and output a second signal indicative of a steering action. The power steering system is in communication with the autopilot system and is arranged to pivot or turn at least one of a rudder and a propulsion unit based on the second signal.

A steering control system for a watercraft includes a pivoting steering tiller manually operated and operatively connected to a direction changing member acting on or into the water, such as a rudder blade or an outboard motor; and a system locking the steering tiller in the steering position, which can be activated for keeping the tiller in a predetermined pivoting position and deactivated for allowing the tiller to be moved in a pivoting position to carry out a change in direction. According to the invention the locking system is switchable by way of switching actuators that are controlled by a control member provided on the arm.