The classic salmon pool usually consists of a head, a main body and tail. So, which part of the pool is most productive when fly fishing? This usually depends on where the salmon are lying in the pool itself. Where salmon lie in a particular pool depends on a multitude of factors. Firstly, it depends on the pool itself and its unique characteristics. It can depend on the speed of the current, the depth and also the character of the river bed in different parts of the pool. Another factor is the character of the river itself. A small, intimate Highland river like the Alness is quite different in nature and character to the mighty River Tay. On some highland rivers, the heads or tails of pools fish better, but again, it depends on the character of the pool itself. For example, I have found the tails of many of the pools to be the most productive on the River Alness. Other factors influencing where the fish may lie in a pool include the time of year, water height, temperature and time of day.
Each angler usually has a preference for which part of the pool they prefer fishing, which can depend on the pool itself. The head of a pool usually has the fastest current. I have found the heads of pools can be more productive in low water conditions, especially in the summer. I am not sure why this is, but it could be because the fish like to lie in the more oxygenated water. Due to the faster current at the head of the pool, there is usually more oxygen available for the fish.
Another aspect I like about fishing the heads of pools is being able to dibble a fly. This is a method that I love because it's so visual and exciting. It is particularly effective in pools on smaller rivers with narrow necks. The idea is to skate the fly across the top of the water on a very short line (sometimes only using two or three feet of fly line) and wait for a salmon to come up from the depths and engulf your fly as it dances on the surface. This method is particularly deadly for grilse in the summer when the fish are lying high up in the head of a pool. I suppose this method is the equivalent of dapping on still water.
Another observation I have made is that I have caught more fish from the head of a pool early in the morning. When I say early, I mean at first light in the summer. My good friend and ghillie on the Thurso River has an interesting theory about this. He believes that salmon are more prone to lying in the heads of pools through the night and early in the morning when there is less light. This is because fish have more confidence in entering the shallower water in low light conditions. As the sun comes up and the temperature rises, the fish then drop back into the safety of the main, deeper body of the pool. In addition to catching more fish early in the morning in the heads of pools, I have also made an interesting observation that may support his theory. Usually when I have started fishing at first light in the summer, I have often seen more fish showing at the heads of pools. As the sun rises, the fish show less at the head and more in the main body of the pool. This is not to say, of course, that all the fish have moved from the head of the pool and dropped back down. This is why sometimes the time of day you are fishing can dictate where the most productive part of the pool is.
The time of year can also be important in determining where the fish will most likely lie in a pool. In the spring, when water temperatures are low, the fish have a slower metabolic rate and are less active. They, therefore, often lie in the deepest and slowest part of the pool. This is usually not the head of the pool, so if the deeper and slower part of the pool is the body or tail, the fish are likely to be in this area. In my experience, the heads of pools are most effective in summer when the water temperatures are high and river levels are low.
The tail of a pool usually has less current than the head. In some pools, the tail can be faster than the main body of the pool. Usually, this is because the tail of the pool is a bit narrower and shallower than the main body. I have found the tails of pools that pick up in current are particularly productive.
In higher water, the tails of pools can be more productive than the heads. This is usually because there is less current in the tail, which makes it easier for the fish to lie there. The extra water also gives more depth to a pool's tail, providing the fish with more security. The tail of some pools can be more productive in the spring and autumn. There could be two reasons for this. Firstly, the tail of the pool can often have less current than the head, so fish are more likely to lie in the tail during the early part of the season, as they have to expend less energy. Secondly, salmon are more likely to spawn in the tails of pools with a slow but steady current. I have caught a bigger proportion of my fish from the tails of pools in September and October. I have also observed that these are usually resident, older fish. This especially rings true if the river bed in the pool's tail mainly consists of gravel. In the autumn, if you have a pool with a tail with a steady current with good depth and a river bed primarily consisting of gravel and boulders, this part of the pool will likely be productive. Many of the fish lying in this part of the pool are likely to be fish that will spawn in the area, and having gravel makes this an ideal habitat. Also, resident fish, which have been in the river for months, will likely have used up much of their energy stores. Lying in the slower tail of a pool allows them to conserve energy and prepare for the all important spawning process.
Obviously, you cannot generalise which part of a pool is better as there are so many variables. However, it is worth bearing in mind that where the fish lie in a pool can change not only from day to day but also hour by hour. I have had more success in the heads of pools in low water in the summer and the tails of pools in the spring and autumn. So instead of heads or tails, it maybe should be heads and tails!
