A co-planar differential pressure sensor module and method of construction thereof is provided which is suitable for submersion in seawater. The module includes a base having a pair of recesses. A pair of pedestals is also provided where each pedestal is disposed in a respective recess and is coupled to a respective isolation diaphragm. A differential pressure sensor has a sensing diaphragm and a pair of pressure sensing ports. Each port of the differential pressure sensor is fluidically coupled to a respective isolation diaphragm by a fill fluid. The module also includes circuitry coupled to the differential pressure sensor to measure an electrical characteristic of the sensor that varies with differential pressure. The base is constructed from a material that is suitable for submersion in seawater.