Today, we're going to start simple, by explaining the difference between a boat and a ship, something you'll need to understand if you're chatting with a sailor, particularly one that serves aboard a submarine.
The typical rule of thumb, according to the Naval Education and Training Command, is that you can put a boat on a ship, but you can't put a ship on a boat. In other words, if there are smaller boats, like lifeboats, dinghies or runabouts that are onboard, the vessel is a ship. Things get more complicated than that – cargo vessels on the Great Lakes are commonly referred to as boats, despite their very large size – but we'll maintain our focus on the military.
In the US Navy, every commissioned surface vessel is a ship, from the hulking Nimitz-class aircraft carriers to the tiny Cyclone-class patrol ships, hence the USS (United States Ship) before each of their names (non-commissioned ships wear the "USNS" designation). Submarines, meanwhile, are boats, despite wearing the same "USS" moniker. The reasoning for this isn't entirely clear, although as is so often the case, it's naval tradition, which tends to supersede all else.
If you have any suggestions on a phrase you aren't sure about, be sure to reach out to brandon dot turkus at autoblog dot com, and we'll be sure to feature it in the coming days.