GPS/GSM Trimix Computer


One important issue for divers is orientation. Till Prototypenow divers use a watch, depth gauge and compass for navigation if visual orientation points fail (caused by e.g. bad visibility or no contact to the sea bottom). Recreational divers have to navigate, if they want to dive individually without dive guide. Special forces are often dependent on precise navigation to fulfil their mission – which is difficult especially in the presence of currents. The safety of a diver is increased, if there is the opportunity to communicate with the outer world. Especially in critical situations (like unexpected strong currents, the lost of the diving boat or decompression gas) this may be of vital importance.

The present work describes a new kind of dive computer, which provides navigation and communication assistance via GPS and GSM. The basic idea is to provide a dive computer / buoy system, which is small enough to fit into a pocket of a BC. If there is a need of navigation assistance or communication via GSM, the small buoy can be set. If the buoy reaches  surface, it connects to GPS and GSM. Predefined SMS can be sent and direction and distance to previously predefined GPS-Coordinates can be shown. The buoy is connected to the dive computer via a thin cable on a reel.

Core component of the dive computer is a low Buoypower microprocessor. A digital temperature and pressure sensor is integrated in the design. A 128x64 matrix display is used to visualize all dive computer specific parameters, plus distance and point of the compass to a preset destinations. The dive profile is continuously tracked and stored into an external memory chip. To provide GPS and GSM functionality is integrated in a buoy system, connected to the dive computer.

The buoy can be set, whenever GPS/GSM is necessary or it can be continuously dragged behind the diver  (f.i. in a country where a buoy is mandatory anyway).


This project was done by our team in collaboration with the Scuola Superiore Sant Anna, Pisa, Italy and CNR - Institute of Clinical Physiology, Pisa, Italy.



B. Kuch, G. Buttazzo, E. Azzopardi, M. Sayer and A. Sieber, „GPS diving computer for underwater tracking and mapping“, International Journal of the Society for Underwater Technology, Vol. 30, No. 4, pp189-194, 2012






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