Patent ID: 7272074

Claim:
An underwater navigation system comprising: a surface unit adapted to float on the surface when deployed, said surface unit including: a receiver to receive navigation signals from earth-orbiting satellites, a sonar transceiver to communicate with to sub-surface beacon units and to transmit location information to said sub-surface beacon units; processing circuits to determine a location of the surface unit based on said navigation signals and to generate a control signal for sinking or destroying said surface unit after transmitting location information to one or more beacon units; a plurality of beacon units adapted to sink to the sea floor when deployed, each said beacon unit including: processing circuits to determine the location of the beacon unit based on location information received from the surface unit; and a sonar transceiver to receive said location information from said surface unit while the surface unit is floating on the surface; and to transmit location information to a diver unit to provide navigation assistance to the diver unit.