a dingy?
A small craft that float on water is commonly known as boat. a boat may carry about a maximum number of a hundred people. The larger one's with greater number of goods and people is called ship.
boat
A rowboat?
Kayak
Some small narrow boats are called canoes, others are called kayaks.
It's called a tug boat
Sometimes it's called a tinnie.
dinghy
canoe
punt
pedalo
captain A boat driver.. if you have a small boat you are obvously not a "captain" in the sitcom "Giligan's Island" the "boat driver" was the skipper