Abstract: The present invention provides apparatuses and methods for alleviating impact of underwater pressure upon submersible devices and emitters. An interior space of the casing of a submersible device may be filled up with fluid to reduce the impact of underwater pressure. The submersible device may further comprise a pressure adjusting bladder attached to the casing through a structure that permits flow of fluid from the casing into the bladder. The bladder may enable the device to cope with varying degrees of fluid expansion due to changes in surrounding pressure or temperature. The submersible device may also comprise a special type of fluid and specially designed internal components so that the presence and flow of the fluid within the device do not affect the performance of the components.

Abstract: Emitters for locating an item or person who as in some way become separated from their expected location are provided. The emitters of the present invention comprise a power source, a light emitting means, and a radiowave emitting means, the light emitting means comprising a first and second electrode, a dielectric material and an electroluminescent material being provided between the first and second electrodes, the radiowave emitting means comprising an antenna. The antenna may comprise the first and/or second electrode. The emitter may be a separate unit or may be part of or attached to an item such as a survival suit, a waterproof suit, a wet suit, a dry suit, a diving suit, a coat, a waterproof coat, a harness, a buoyancy item or aid, a life jacket, a life raft, a lifeboat, a floatation aid, a life belt, etc.