Both turn the rudder. A tiller is a handle fixed directly to the rudder and you push it the opposite way to the way you want to turn; a wheel turns the rudder through a mechanism and you turn it the way you want to go, like a car.
A tiller is a long handle attached directly to the top of the rudder. Moving it swings the rudder the opposite way, so you push the tiller the opposite way to the way you want the bow to go. Push it towards the sails and the boat turns towards the wind; pull it towards you and she turns away. This feels backwards at first, but soon becomes automatic.
A wheel turns the rudder through cables, rods or hydraulics. You turn it the way you want to go, as in a car: turn it to starboard and the bow goes to starboard.
Each has its advantages.
- A tiller is simple, light, and connected directly to the rudder, so you can feel exactly what the boat is doing through it. A boat with too much weather helm pulls on the tiller, which tells you the sails need adjusting. Dinghies and most smaller yachts have tillers.
- A wheel gives more leverage, which bigger yachts need because the loads on the rudder are much larger. It doesn’t sweep across the cockpit as a tiller does, and the helmsman can stand behind it. Most larger yachts have wheels, often two, one on each side.
Whichever you use, the rudder only works when water flows past it. At speed a small movement is enough; at low speed you need much more; and when the boat is stopped it does nothing at all. Steer with small, smooth movements and give the boat time to respond before you move again. Over-steering is the commonest beginner’s habit.
Boats with a wheel normally carry an emergency tiller that fits directly onto the top of the rudder stock in case the steering fails. Find out where it is kept and how it fits before you need it.
More in the book: Chapter 6, Steering and tacking