Instead of hijacking the Ditch Bag post if anybody is interest lets start over.
Would a on / off indicator run off the bilge switch serve? Depending on how much time we have, I can certainly understand having an additional water alarm. Although, I am not too worried because I compulsively check the engine compartment while I am on the boat.
That would only tell you if the bilge pump is on, not if the there is water in the boat. If you had a blown fuse or a pump that was not working them what?