US Patent 7852710 Tide display device with global positioning system, timing and navigation

A global positioning system (GPS) receiver may be integrated with a tide display device. The GPS receiver receives satellite signals and determines the precise time and geodetic position by trilateration. The precise time and geodetic position is used by the tide display device to determine the appropriate tide information to display. The tide display device displays the tide information to a surfer on a graph display with the ordinate axis representing tide height and the abscissa axis representing time.