Johnson Boat Bilge Water Alarm The Bilge Alert high water detection alarm by Johnson uses a field effect technology to detect the presence of liquid. It is able to detect liquids with no moving parts. Highly reliable and durable this Boat Bilge Alert uses advanced sensor technology. After 8 seconds of being exposed to water the detector activates a 100 db alarm Specifications 12V DC Power Voltage rating 10.5-14.4 V DC BILGEALERT 12V California Residents WARNING Cancer and Reproductive Harm - P65