The captain of a ferry appears to steer or drive it. What is the correct verb for this?
Captain is a verb; and pilot is a possibility too, although that has a specific meaning with regard to ships [a shipping pilot is usually someone who is locally skilled and will successfully negotiate hazards around a harbour].
verb [with object]
be the captain of (a ship, aircraft, or sports team):
all the boats are captained by professional sailors
the person in command of a ship
pilot verb (pilots, piloting, piloted)
be the pilot of (an aircraft or ship):
he piloted the helicopter from Paris to Deauville
a person who operates the flying controls of an aircraft
A captain (as well as captaining) navigates (guides it over its route):
2 [with object] sail or travel over (a stretch of water or terrain), especially carefully or with difficulty:
ships had been lost while navigating the narrows
the drivers skilfully navigated a muddy course
• [no object] (of a ship or boat) sail; proceed:
[with adverbial of direction]:
we sailed out while navigating around large icebergs
• guide (a vessel or vehicle) over a specified route or terrain:
she navigated the car safely through the traffic
While I agree with the other answers, there is nothing wrong with steering a ferry. At least, it sounds right to me and the Free Dictionary seems to agree with me (emphasis mine):
v. steered, steer·ing, steers v.tr.
- To guide by means of a device such as a rudder, paddle, or wheel.
- a. To direct the course of. See Synonyms at conduct.
b. To maneuver (a person) into a place or course of action. See Synonyms at guide. v.intr.
- To guide a vessel or vehicle.
- To follow or move in a set course.
- To admit of being steered or guided: a craft that steers easily.
The word's etymology also supports nautical usage (emphasis mine):
"guide the course of a vehicle," Old English steran (Mercian), stieran (West Saxon), from Proto-Germanic *steurijanan (cf. Old Norse styra, Old Frisian stiora, Dutch sturen, Old High German stiuren, German steuern "to steer," Gothic stiurjan "to establish, assert"), related to *steuro "a rudder, a steering" (cf. Old English steor "helm, rudder," German Steuer and first element in starboard), from PIE *steu-ro- (cf. Greek stauros "stake, pole"), from root *sta- "to stand" (see stet).
The notion is of a stiff, upright pillar or post used in steering.
There is more to driving a road vehicle than steering it and there is more to controlling a boat or ship than steering it too, it is also necessary, at least, to specify the speed and the forward or backward direction of travel.
In the case of a road vehicle or a powerboat where one person is in direct control of all aspects of the operation (speed, gears, direction, safety, compliance with regulations and so on) the term driver is used almost exclusively. British Waterski and Wakeboard certainly think that the people controlling their towing craft are drivers and the Royal Yachting Association also think that powerboat operators are drivers.
In the case of larger vessels such a ferries (which are large enough to be considered ships) the control is more devolved, there will be a helmsman (helmswoman?) who steers the vessel; there will be engineering crew who are responsible for the speed of the engines; there may be lookouts who are watching for other vessels and hazards; and there may also be crew members who are responsible for operating car deck doors, placing fenders and handling ropes when the vessel docks. All these functions are part of what a driver does but they are devolved to different people.
The captain or skipper of such a vessel must decide where the ship is to go, what speed she is to make and the direction of travel (forwards, backwards or even sideways if thrusters are employed) but will not, usually, be touching any of the controls directly. Thus the captain is commanding or possibly skippering the vessel but is not driving it.