Shipwrecks and Undersea Features
Take the list of the seas in the Mediterranean area.
Download shipwreck data for that area.
Plot the individual shipwrecks as points on a relief map.
These are the depths of the places where the shipwrecks took place.
You can see that they accumulate around the coasts, with a secondary peak around meters, corresponding to the most common non-coastal depth in the Mediterranean.
There is no clear correlation with the collection of undersea features for the Mediterranean area.