marine batteries submerged

My boat just recently sunk due to the bilge pump failed. My question is the marine batteries that I had on board look alright but will they still work?

Are they sealed batteries? Your best bet is to take them to an auto parts store and have them tested.

How long was the boat under water?

Odds are, that if they weren't sunk too deep (water pressure) or too long, they will be fine. I had an automotive battery that was submerged in 2 feet of salt water for 5-6 hours and it was fine. Rinse the battery off with clean fresh water (distilled is even better) and dry it off before you open the caps. Check the electrolyte level andif it is normal you probably don't have water intrusion. If they are full, you might be looking at needing a new battery. Either way I would take it in for a load test. Good luck.