A boat auxiliary motor support, comprising a base, a bracket and two levers between which is mounted a control system comprising one cylinder, one piston and one hollow piston rod containing a control rod free to slide axially. The interior of the cylinder is divided up by a floating piston into a chamber filled with gas and forming a gas sprint and two chambers filled with oil and separated by the piston. The control rod rests against a valve mounted in the piston, that allows the oil to flow from one chamber to the other through a duct. A control system is mounted at the free end of the control rod to open the valve.