An actuator (10) for use in controlling movement of a component (22) of a seagoing vessel comprises a cylinder (12) for coupling to a vessel hull (14) and an actuator shaft (18). A distal end (20) of the shaft (18) is coupled to the component whose movement is to be controlled and, in use, a control force (Fc) is applied to the shaft (18) to control movement of the shaft (18) from a first position, retracted, position to a second, extended, position. The actuator (10) is compliant in response to an opposing force exceeding a selected force to prevent or mitigate damage to the component (22) and/or the actuator 10 which may otherwise result from the opposing force.