I must be getting old… If it can be picked up in a davit, then it’s a boat…
After my Navy time, and having shown the proper qualifications as Officer fo the Deck (Underway) for a Spruance class Destroyer, I was cleared to sit for a 1600 ton ticket. When I asked why it wasn’t an unlimited due to the tonnage, I was told emphatically that “Military vessels didn’t qualify as ships”.
Interesting… By the way, my evaluation was done by an active duty Coastie, not a civilian.