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Abstract

A new device has been developed for measuring wave pressure at the field level. It is configured with a pressure and 3 directional acceleration sensors as well as a self-recording system with 32 MB memory. It can work for 45 days with a cell battery under 20Hz sampling frequency and costs less than one tenth of the existing cable type pressure measuring systems. Performance of the device has been tested on an upright section of a breakwater on coral reef flat in Okinawa of Japan. Data obtained shows that the new device may treat as reliable. The pressure acting on a breakwater on the reef flat is strongly influenced by the water surface level rise of surf beat waves. Pressure distribution shows that pressure due to a short period wave can be estimated by the partially reflected wave theory, so that the resultant depth of still water level, wave setup and surface level rise due to surf beat wave can be regarded as the design water depth.