France Telecom R&D, in partnership with Amphicom, has recently invented a system that allows telephone communications with a diver working underwater. The system reportedly ensures a clear connection from a fixed or wireless phone to a person working underwater at any depth.
The system comprises a buoy fitted with a GSM phone relay that handles two-way communications with an underwater terminal. The terminal is connected to the buoy by a wire, and is equipped with a dial pad, a special mouthpiece, a light and a buzzer.
The buzzer and a flashing light alert the diver to an incoming call. The parties are able to talk because of the ability of bones to conduct sound underwater. The sound wave from the surface transits through the system to the mouthpiece.
The diver has to bite down on the mouthpiece and push a button to unhook the handset. Sound vibrations propagate to his ear via his skull, which acts as a resonance chamber and he or she can then clearly hear the incoming call and also talk back in half duplex mode.
With the dialling pad, the diver can also call anybody on a fixed or wireless phone. Since the end of last year, the system has been tested by marine archaeologists at the Alexandrine Research Centre in Egypt.
The new underwater communications system should be commercialised by the end of 2002. France Telecom’s research teams are already said to be looking at ways to eliminate the wire link between the buoy and the submerged terminal, so that divers are totally independent.
This also means that members of a team diving in the same area can call each other whenever they want. Two possible solutions to transmit voices under water are now under study: ultrasound waves, or weak electrical currents.