A cableless data acquisition system for self-recording seabed-installed type wave gauges is newly developed by using 100KHz ultrasonicacoustic signals in the sea water.
　Model tests using water basins have been conducted several times during 1995 and 1996, and the system design was completed. Various types of field tests were also conducted in the Numazu-Bay, the Tokyo-Bay and the Sagami-Bay areas repeatedly during the years from 1996 to 1999, and validity of the system has been proved.
　This paper introduces the basic concept of the cableless data acquisition system and results of the water-basin and field tests.