IT could be argued that a boat is just a generic term for 'watercraft' everything from a seadoo to a container vessel.
And a ship is a subclass of boat.
And a ship is a subclass of boat.
What would you call a surf or kiteboard instead?
I think that those could be grouped together but would require a new category that may or may not include water skis or wakeboards. Another condition i was thinking about placing on boat was a steering mechanism akin to a rudder but then realized rowing shells often don’t have those although I’d consider them boats.