GROS JACQUES (JACK)
18.43027 deg N, 72.74943 deg W.
The gauge is a piezometer arrangement consisting of a pressure gauge buried beneath the beach and attached via a stainless steel bar to a concrete sea wall.
The top of the steel rod was leveled to a nearby inland pin to provide a check on long term subsidence of the sea wall, and the stability of the pressure transducer.