Abstract: A water-activated survival lamp unit for mounting to a flotation device in proximity to the water line. The survival lamp unit comprises a hermetically sealed light transmissive housing in which are mounted a light source and a battery in an electrical circuit together. A water-responsive actuator is provided, including a pair of electric terminals extending outside the housing in a spaced apart relationship. The actuator is responsive to a momentary electrical path established between the terminals through a coherent body of water to close the electrical circuit between the battery and the light source for a predetermined time period largely exceeding the duration of the electrical path, thus causing timed actuation of the light source. Periodic water splashing of the electric terminals allows to reestablish at intervals the electric path, each time resetting the actuator which closes the electrical circuit for an additional time period.