專利摘要：
An underwater electromechanical timer comprises a motor-driven timer assembly which includes a threaded member that engages an endless screw driven in rotation by means of a motor. Time programming of the timer is accomplished via presetting a length of sliding of the threaded member along the endless screw. The sliding threaded member causes a timely switching event of a device switch placed in the casing structure. The device switch, electrically connected to an external device, thereby activates the external device. The underwater electromechanical timer is activated via an activation mechanism that is externally exposed. Under an external pressure, the activation mechanism connects an output of the motor with the endless screw, and further turns on the motor. Resilient elements are further mounted between the motor and the endless screw and between the threaded member and the device switch to prevent undesired activation events.