None of those have an engine, which both the first and third definitions would say is typical.

That's why the only vehicle that made me pause was the tank, since it was at one point motorized, but no longer.

I interpreted the tank as a form of sculpture, not a vehicle.

Typical, sure, but not required!

This is why legal documents often have important definitions listed. In the last case, the answer hinges on the definition of “machine”. Pick a definition of that, and I’ll tell you if a boat is a vehicle.

Let's stick with the Cambridge dictionary:

> a piece of equipment with several moving parts that uses power to do a particular type of work

How many oars is "several"? Do they count if they're not physically affixed to the boat?

Continuing to stick with the Cambridge Dictionary.

> ((a piece of (the set of necessary tools, clothing, etc. for a particular purpose) with (some; an amount that is not exact but is fewer than many) moving parts that uses power to do a particular type of work) used for transporting people or goods)

Yup, that's technically a rowboat - as long as it has oars included (whether or not they're physically attached: "set of"). Take the oars out of the equation, and it's not a machine anymore...just a piece of a vehicle (like how a tire isn't a car).

This definition excludes cars, right? “Many” is pretty vague, but I think we can agree it describes the number of moving parts in a car.