So at this point you're probably saying to yourself "Hey, that ship is huge and all, but he said there were 300 ships here! Where are the rest of 'em?". Calm down and
stop saying the word "ship" so much that it loses all meaning direct your attention to the map below, you'll find your answer.
See those ship-shaped silhouettes in the top-left corner? Most of the dead vessels here've sunk to the bottom and can't be seen from the surface. Total bummer, right?