Front Bow U Bolt Coming Out???

I have a 1996 Caravelle and the front u-bolt where you hook the winch to is starting to pull out. I was wondering if anyone has any experience as to how to fix this? There is no way to get to the inside to tighten the nuts or add a backing plate. There is an integrated cooler in the nose, and I can't reach the back of the front cushion to take off the nuts and remove the cushion. I am worried that the u-bolt is going come all the way off when I am pulling the boat out and the boat will end up on the ramp.