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.
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
If the boat has an oarsman...a Coxswain.
helm
a helm or a helms man is a person who steers the boot or submarine
coxswain
move side to side
In ships or ferries, the person who steers is called a helmsman. In relatively small boats, the person that steers the boat is called a skipper.
A steering wheel would steer a boat, and a captain would be controlling the steering wheel.
Normally a rudder is used to steer, but it depends on what boat your on on what the rudder steers. For example- a motor on a jet boat and a tilla on a sailing boat.
No, a tiller or steering wheel steers a boat.
A wheel or a tiller is used to influence the direction of the rudder, which steers the boat.
It is dependant on the boat. FOR QUADS - either a cox (person who steers the boat) or it is just by pulling harder on one side EIGHTS - cox SCULLS - pulling harder on one side PAIRS - usually pulling harder but sometimes a cox