RE: Submarines are not ships. They are boats.
But aren’t ships, boats?
All ships are boats but not all boats are ships.
Dictionary definition: A boat is a watercraft of any size designed to float or plane, to provide passage across water.
Navy 101: Ships have a pointy end and a blunt end.
There are two types of naval vessels, in the humble opinion of the US’s Silent Service (Submariners).
Submarines and targets. Deo Vindice.