It is not really all that silly.
Mankind has been sailing on the Mediterranean for thousands of years in various manner of vessels. It is a bit on the shallow side and has a reputation for getting snotty fairly quickly so it stands to reason that many boats line the bottom of that sea as there were more of them exposed to bad conditions that they could not handle over the ages. We really do not know how many boats are sitting on the bottom of the ocean in say, 6000' of water as we can't find them quite as easily as they can be found in the Med. There are many vessels that were just marked as 'overdue' that never arrived at their ports of call and were presumed lost. Today things are only a little different now that we have better building materials for ships, electronics and satellite technology to help us.
To harken back to Tommays point about the LI Sound being a rough body of water because it is more shallow and therefore rough in a blow: at least a big ocean going vessel can wait out at sea before trying to come into an area where there are lots of pointy rocks and bits of land they could run into. In the old days ... glub, glub, glub. Even the Great Lakes of the US have a pretty fearsome reputation for swallowing ships and they have lots of shoreline too. Anywhere near shore is a danger for a large seagoing vessel. Staying in the big water is generally safer for them - not for us little guys, even though we risk running aground and all the other hundreds of things that could go wrong.
Plenty of boats lost in both the Arctic and Antarctic. Plenty of boats have been lost near all coasts due to gales. Even with today's technologies there are shipping disasters happening all over the world right now (and I don't just mean off the coast of Somalia). Click this link and scroll down a bit for the 'Daily Casualty Report':
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