Rule Hi-Water Boat Bilge Alarm System These High Water Bilge Alarms consist of a non-mercury float switch and an in-dash gauge that feature both a visual and an audible 85 db alarm. This unit allows an unmanned compartment to be constantly monitored. For additional compartments you need only add additional Rule Float Switches. Complies with CFR 182.530 which requires a visual and audible alarm in each unmanned space on commercial vessels at least 26 7.9m in length Specifications Volts 12 Max Am