It wasn't just waves that sank the ship. First, the ship scraped over a ridge of submerged rock that cracked or weakened the hull. The crew as unaware of the damage. Later, when in really high waves of an unlucky wave-length, one wave lifted the bow and another lifted the stern, and the ship broke all the way in two.

I forget where I read this, but it was from a reputable source and it's all in the previous thread on this ship.