Larry ... Last year I blew a belt, granted the engine had been running for some time. I heard a bang from the cockpit, but that was it, no other indication, so by the time I started looking around for what happened, which was a couple minutes, the alarm sounded, so I turned off the engine, pulled the engine compartment off and saw the shreaded belt. The alarm was quick, the temp sensor is attached to the raw water exhaust.

I also have their bilge alarm. Fortunately, that has not ever gone off ! Touch wood.

http://www.borelmfg.com/store/details.asp?cscpid=1294

Cheers, John