In this article, the fault-tolerant control problem against thruster faults is investigated for unmanned marine vehicles. The main approach is, for the first time, based on integral sliding mode control technique where only measurable outputs of unmanned marine vehicles are used. By using matrix full-rank decomposition and adaptive mechanism, an output integral sliding surface is constructed and an integral sliding mode controller with a full-order compensator is designed to attenuate the oscillation amplitudes of the yaw angle and yaw velocity error in the presence of thruster faults and ocean external disturbances. Through a typical floating production ship, the effectiveness of the proposed method is verified in the simulation example.