Those things get you when you least expect it. We had a ton of rain the other day while the boat was at the canvas shop. The float switch was off (yes I have it switched because I live in a place where it rarely rains and a dead battery is usually more likely) so I ended up with 1' 1/2 of water in the bulge!! I don't think my batteries submerged but I guess I'll find out if my dry boxes are. Only think that might have been damaged was the slow charger. Not sure if the water made it to that. I don't think so.