Yea there are some really good strong magnetic tool retrievers. I think it could really cause issues, even rough seas could cause this to go through the tank if it happens to hit a weak spot that it had been sitting on causing it to corrode. I saw a flexible tool grabber that had a magnetic pickup in the center at either Lowes or Home Depot. The biggest issue is that the magnet did not seem very strong, but should hold onto the file enough to let the claws to hold on to it. Good thing was it was like $2.99 or something. It was in one of the cardboard displays in the middle of the row in front of the tool section.