My guess would be that if the waves are high enough to sink the boat (10'ers) you would be in a lot of trouble. The boat should float near the surface. But how are you going to stay in the boat?
I was out with a friend in his closed bow boat and we speared a wave. I thought it was going down because we had over 1' of water on the windshield. It felt funny sitting below the water. She popped back up and i started to bail the 1' of water out of the bottom of the boat. If that was an open boat she would have went right down. I thought he new how to drive a boat but i was wrong.
Hopefully we will hear some good stories.