helm
A steering wheel would steer a boat, and a captain would be controlling the steering wheel.
If the boat has an oarsman...a Coxswain.
It could be anyone. But mainly the helmsman, but it could be the Skipper (Captain) if it's a small sport boat like a bow-rider. But normally the owner of the boat or person hired to Captain the boat drives the boat or the helmsman.
coxswain
a helm or a helms man is a person who steers the boot or submarine
The rudder is the part of the boat that steers. Although the tiller or wheel literally steers the boat, the rudder is in the water, moving with the tiller to change the direction of the boat
Ahab
The Endeavour
Discovery
his boat name was the PT-109 and he was the captain of it!
move side to side
The "Black Pig"