What would cause a boat 's bow to dig into waves ?
The subsequent failure of the bow ramp allowed water into the vehicle deck , which was listed as the main cause of the capsizing and sinking : RORO ferries with their wide vehicle decks are particularly vulnerable to capsizing if the car deck is even slightly flooded because of free surface effect : the fluid 's swilling motion across such a large area hampers the boat 's ability to right itself after rolling with a wave .