Abstract: A safety device for locating an individual fallen into the sea includes a visual indicator in the form of a dye and an intermittently operated lamp (3), and a radio transmitter (9) for transmitting a radio signal. The dye is contained in a vessel (4) having a trap door and control circuits (12) are provided having a power source (5) and automatically operated by a water sensitive microswitch (10) to open the trap door of the dye vessel (9), energize the intermittent lamp (3) and energize the radio transmitter (9), all of the components being integral with a helmet (1) worn by the individual. A radio receiver may also be provided on a boat for receiving signals transmitted from the radio device and guiding the boat to the radio device.