If those of you who own thick" hulled boats believe that the fibreglass will save you when things get really bad, I am happy for you! The fact of the matter is that no boat would survive the pounding that boat was subjected to, let alone a person trying to hold on....! Ever walked through a junkyard and studied wrecked cars?. If the forces are severe enough you will not survive. We are not talking about a gentle grounding here....
Bruce