Abstract: A wheel drive for a boat steering wheel comprises a front drivable ring for clamping to the spokes of the wheel, and a driving part including an autopilot-controlled motor supported on a rear ring that is itself supported on the front ring by a series of circumferential rollers engaging a grooved path around the front ring. A torque reaction engagement between the rear ring and an adjacent object prevents rotation of the driving part so that the motor can drive the front ring and the wheel in rotation by means of a drive belt. The engagement does not carry the weight of the driving part, which forms a self-contained unit with the drivable part.