Maretron NMEA 2000 Bilge High Water Detector (SIM100 Accessory) BHW100Maretron NMEA 2000 Bilge High Water Detector (SIM100 Accessory) BHW100 The BHW100 sensor has a target molded into the plastic enclosure (opposite the side with the Maretron label). The target should be exposed so that when the water rises above the middle of the target, the BHW100 will indicate high water by illuminating the red LED and sending a signal to the Maretron Switch Indicator Module (SIM100). The BHW100 is mounted to a vertical wall in the