EurOCEAN 2000 - Vlaams Instituut voor de Zee

The electrochemical effects on the electrical consumption (for a given ranging) have been
studied. These losses can be minimised by finding a compromise between the electrode surface
and the current density. Ranging versus power charts have been established for different types
of emission electrodes, in order to quantify the respective influence of the electrodes diameter
and surface.
The electrical safety criteria [9-15] have been studied depending of the diver clothes (short,
diving suit, gloves). The human body admissible current criteria for a contact longer than 10s is
10 mA (IEC 479 safe curve for a.c. current). For the case of 30m range communication
between divers wearing only shorts (worst case, 1m 2 of electrical contact with water), the
electrical safety is achieved with reasonable size electrodes. The electromagnetic effects are
under study but their environmental impact is more difficult to establish.
CONCLUSIONS
The development realised on the scuba mouthpiece insuring communication through bone
audio conduction is now finalised on a first serial product using plug to plug conduction
(SCAPHONE ® , distributed by TFE company). To achieve the final step of diver born product,
the water transmission will be more deeply studied (signal modulation, simulation of induced
magnetic field and frequency skin effect on the power ranging).
ACKNOWLEDGEMENTS
The partners wish to acknowledge the European Commission and the Office Fédéral de
l’Education et de la Science (OFES) for their financial support.
REFERENCES
[1] MacLeod NC (1977) : « Electric diver communication : Non acoustic system can operate
in noisy environments », Sea technology
[2] Williscroft RG, MacLeod NC : « A non-acoustic long distance underwater communication
system »
[3] E.C.Brainard, Gen Time Corp (1972) : «Underwater communication system » , US Patent
N° 3 668 617, June
[4] A.Prichodjko (1973): «Procédé de transmission radioélectrique des signaux et
dispositions nécessaires à sa réalisation», Deutsch patent No.23 48 72
[5] N.C.MacLeod, Technology Development Corp (1980) : «Underwater communications
system»., US Patent N° 4 207 568 June
597