A directional control system for a marine vessel comprising a steering mechanism movable between two extreme opposite positions and capable of altering the direction of the marine vessel; an actuator for moving the steering mechanism between the two extreme opposite stop positions; a directional control station comprising a control element movable between two opposite positions to set a directional steering; and an electrical transmission system transmitting to the actuator the movement stroke of the control element or the position of the control element in the total stroke between the two opposite stop positions. The electrical transmission system transforms the movement stroke of the control element, or the position of the control element, into an actuation signal for the actuator according to a function univocally correlated with the position of the steering mechanism, thereby causing the steering mechanism to assume a steering position that directly corresponds to the actuation signal.