Reading Water According to Fish Patterns
One of the first concepts that fly fishermen should learn is the ability to read water to determine which places in a river are the most likely to hold fish. However, another critical thing to learn is the patterns of fish movement for your particular waters. You need to know which water types will hold fish at certain times and when fish move into and out of them. Here are a few things to remember when reading water to find those feeding fish.
In fast streams with a high gradient and lots of pocket water fish will almost always hold on the downstream side of rocks in the slower currents provided there. This makes it possible for them not to expend too much energy. However, in large hatches where a lot of food items are drifting by, remember to look or cast in front of rocks and into faster currents. Sometimes the chance to find enough food in faster currents makes the energy expenditure worth it and fish will feed there and then move back to slower pocket water once the hatch is over.
Don't overlook fast water in low oxygen situations. Often in the heat of the summer fish will move into riffles bordering on rapids because of the higher oxygen levels available to them there. Once water cools and is able to carry more oxygen fish will move back into more traditional water types.
One of the first rules fly anglers learn is to look for depth when looking for fish. Don't get too hung up on this practice though as many times feeding fish move into more shallow water where they can catch a meal a little easier.
Always fish shaded spots on bright sunny days but beware that if there is adequate food in the sunny parts of streams that fish will risk the sunburn.
Also learn the particularities of your local waters. Streams with a high fish population will have fish spread throughout the water types while streams with low fish numbers will tend to only hold fish in the most prime locations.
One good way to learn more about where fish are in the waters you fish is to experiment with casts to not so likely looking spots every now and then. You may be surprised at where you'll find fish and you may end up catching a lot of fish that almost everyone else misses.