It is important to note that the rudder will not start to act the instant you move the wires it takes a couple of strokes to work. This delay time is dependent on the speed at which you are moving as well as the size and make of the boat. If the boat is moving slowly you will find that steering with the rudder has very little effect. Therefore if you are moving very slowly (or are stationary) you will have to steer using the crew. It is also important to remember that the rudder will take a corresponding length of time to stop acting so there will be a delay between the rudder being set to the off position and it ceasing to act. In light of this, until you are very familiar with the responsiveness of a boat, you should use the rudder before it seems necessary. This anticipation can be difficult at first but will quickly become second nature. A common error is only to take the rudder off when you are pointing where you want to go. This can cause you to over-steer because of the delay in the reaction of the boat, resulting in a zigzag course.
There are two schools of thought on how to take corners most efficiently. One option is to use the rudder. The other option is to get one side of the boat to pull harder. Most of the time the former will be the more appropriate. When going round sharp corners particularly during a race you might want to get one side to pull harder as well as using the rudder. Some people will tell you that you should only apply the rudder during the drive phase. This has its merits on a straight course but is insufficient on bendy courses and quite difficult to do well. The best approach is to apply the rudder gently, to leave the rudder on for as long as necessary and then gently to take it off again. Try not to ‘pulse steer’, where you steer a little bit on every stroke. This usually results in a snaking pattern, where you steer, over-correct, over-correct, over-correct, etc. It is worth noting that it is the stern which is moved sideways when you apply the rudder, not the bow. Most of the time the difference is unimportant. However, if you are close to a bank and steering away from it, be aware that your stern will move closer to the bank. If this is the case you will have to apply the rudder gently until you have put adequate space between the boat and the bank. It is important to remember that only little movements of the string are necessary to adjust your course. Anything more and you risk setting off balance as well as over-steering.