Float switches must be securely mounted and installed clear of wires, hoses and other obstructions that can impede operation of the floating-arm or flapper switch. Orient the switch fore and aft, with the flapper pointed toward the stern. This is especially important on powerboats; during jackrabbit takeoffs, surging bilge water can damage the flapper mechanism. Installing them close to a bulkhead or frame also helps protect the switch from a torrent of water. Enclosed switches eliminate this worry, but they’re difficult to inspect and test.