Many anglers that have enjoyed a salmon fishing holiday in the Scottish Highlands will be familiar with the technique of “backing up”. Backing up is a very productive way to fly fish for salmon when the water is low. The standard way to fly fish for salmon on any river is to start at the head of a pool and cast at a slightly downstream angle and let the fly swing around in the current. When the fly comes parallel to your own bank, you then take two paces downstream and repeat the whole process. By doing this you cover the whole pool effectively. If there is not much current in some parts of the pool (often in the main body of a slow pool) you may decide to hand line, to give the fly a bit more movement.
When you are backing up you are doing exactly the opposite. The technique can be particularly effective when there is very little or no current in the pool and there is a strong upstream wind. This can frequently be the case when salmon fishing in the Scottish Highlands, as many of the rivers are spate rivers and it can often be windy. Instead of starting to fish at the head of a pool, you start at the tail. You cast the fly directly towards the far bank at ninety degrees and then take two paces upstream. This creates a natural downstream belly in your fly line. You then go on to hand line to give the fly movement, if there is little or no flow. After the fly has come close to the near bank, you cast out again at the same angle and take a further couple of steps upstream. This process is repeated until the entire pool has been covered. Your last cast should be at the head of the pool. This method of presents the fly at a different angle to the fish and often can produce the results.
Many experienced salmon fishers in the highlands will often fish down a pool in the standard way, and then cover it again a second time but this time by backing it up. It is quite extraordinary how sometimes fishing the pool in the traditional way produces nothing but backing it up does.
This is a very popular technique when fly fishing for salmon and is used to great effect on rivers like the Navar, Thurso and Helmsdale amongst others. It is well worth a try when the going gets tough, especially if the water is low and there is very little flow in the pools.