Happy New Year Peter,
Its like the old question, which came first the chicken or the egg.
I’ve always assumed it was a question of size. had a quick search of the web and found a few answers to start you of with – take your pick !
When Paul & Bob get over their hangovers we’ll get nearer to the answer …
Web Answers ….
It’s a question of size. You can put a boat on a ship, but you can’t put a ship on a boat
Why not look it up in a dictionary ? I found these definitions. Ship: "a large boat for travelling on water, esp. across the sea." Boat: "a small vehicle for travelling on water".
A boat is defined as a vessel with a single unbroken deck above the water line. Hence a submarine or small trawler is a "boat" whereas a large cross-channel ferry is a "ship".
Not sure about some of these. Many of the ‘small ships’ from Dunkirk would fit on some of the things described as ‘boats’ at the Boat Show these days. My own 7m ‘boat’ is a ‘ship’ and is registered as such on the Small Ships’ Register (SSR). BUT she was moved on a river boat a few years ago. So a ship CAN go on a boat!
With regard to motorized craft, a ship is a large vessel intended for oceangoing or at least deep-water transport, and a boat is anything else.
Cheers – Ken