Float Switch

A float switch is an automatic level sensor used on boats to detect rising water or fluid and trigger an electrical circuit. In a marine bilge system, it is usually mounted low in the hull and turns the bilge pump on when water reaches a set height, then switches it off as the level falls.

For boaters, a reliable float switch is a basic safeguard against flooding from leaks, spray, rainwater, failed seacocks or plumbing faults. It reduces the need for constant manual checks, protects batteries and equipment, and helps maintain stability. It is closely tied to the Bilge, Bilge Pump and wider Hull integrity.

Float switches may be mechanical, reed, or solid-state sensors, and should be tested regularly for debris, corrosion, correct wiring and free movement. Offshore crews can combine pump status, battery monitoring and onboard alerts through systems such as DataHub, giving better awareness while underway or away from the vessel.