How Do I Nymph a Long, Slow Pool With an Indicator?

One of the most intriguing parts of a river is its deep, dark pools. When you stop to look at one, it’s hard not to imagine those long stretches of slow moving water being stacked full of big fish, lurking on the bottom and waiting to take your fly.

Pools like these are their own little worlds. Fished right, they can provide you with some of the finest angling of your life. Unfortunately, though, they can also provide you with some of most frustrating times you’ll ever have on the water.

In the primetimes of summer, pools like these boil with trout eating dries at the beginning and end of the run. But when the surface is quiet, how do you explore the depths—and get your fly in front of the fish—by using an indicator and a nymph?

Because of their depth, these pools are tough to fish. The deeper you go, the more currents differ and the harder it is to make a proper presentation. So, compared to other pieces of water, you need a different approach for these long, slow pools.

Diving Right In

Let’s say you’re are looking at a pool that begins after a section of riffles. The pool is 40 yards wide and about 15’ deep in the center. There’s a high bank on one side and then a gravel shore on the other. There’s a good current at the head of the pool. But by the middle, this flow slows to a walking pace. Then it picks up again at the tail. There are no fish rising and there’s no visible hatch. But because of the size and depth of the pool, you know fish are down there and you’re ready to go after them with an indicator and a nymph.

Heads First

The first place to focus on is the beginning of the pool where the riffle hits a drop off and the water smooths out as it deepens. Most of the time, any fish feeding on nymphs will be located here. The faster current of the riffle and the drop in depth provides fish with a constant supply of food. These water conditions also provide fish with the cover they need to rise, take a bug, and drop back down to the safety of deeper water. To fish this area right, you’ll want to be sure your fly is drifting correctly.

To make this happen, set your indicator at 1.5 times greater than the depth of the water where the riffle drops off into the pool. You can measure this depth by wading close and estimating or by probing the area with a wading stick or even the tip of your rod (be gentle). While y measurement doesn’t have to be exact, it does have to be close.

With your indicator in place, you’ll need to cast 5'—6’ above the drop off. Then mend, mend, and mend so by the time the fly reaches the drop off, it’s floating drag free and is either on the bottom or close to it. If you’re having trouble getting your fly down, attach a split shot 8”—12” above an your nymph. Fish could be holding at any location along this first drop off, so you should fish this rig all the way across the river.

The Demanding Depths

Once you’ve worked the head of the pool, it’s time to try the deeper water further down. Again, let’s say the pool is 15’ deep in the middle. To find where fish are feeding, you’ll need break down the pool into chunks.

First, keep the same setup you used at the head of the pool and make some passes along the high bank on the far side. The water there will be on the shallower side and the current will stronger. Some fish will position themselves there to catch more drifting insects.

The current in the middle and in the greatest depths is slow, so it brings fish less food. At some times of the year, all the fish in the pool could be along the bank eating migrating nymphs. If you’ve located fish along the bank, fish it hard. If you don’t have luck there, then it’s a good bet fish are holding in deepest part of the pool or in the tailout.

How do you fish a 15’ deep pool with a 9’ leader and a floating line?

  • First, set the indicator at the beginning of your leader.
  • Next, tie on 2’ or so of tippet material and add another fly. This will give you about 11’ of leader in all.
  • Then, place your split shot between the two flies. This will help you get as close to the bottom as you can.

Make some drifts through the pool with this setup. If fish aren’t coming up for your fly, you’ll have to get it bouncing along the bottom and down to them.

To do this, remove the indicator. Then make a cast right at the head of the deepest part of the pool. Mend like crazy so your flies sink. As you do this, you’ll notice the tip of your floating fly line will start to sink, too. Once you feel the bottom, very slowly strip the line back to you. The current at the very depths of the most pools is very slow, and insects there will be migrating by swimming rather than drifting. Stripping your line imitates this movement. Try this out with your heaviest stonefly, crayfish, and sculpin patterns.

Tails Last

To fish the tail of a pool, use the same method you used at the head. Some fish will have moved to the shallowest part of the pool, right above the section where it thins out the most and the next stretch of riffles begin.

The currents in this area rejuvenates the bug life and draws many drifting insects back into feeding lanes. Fish are more than happy to take advantages of these easy meals. By repositioning your indicator and adjusting your flies, you can add your nymph to their menu.

The best aid you can have while dissecting these large deep pools is time. If you really want to find out what’s down there, then you’ll want to have ample amount of time to try a variety of methods and adjustments to your indicator system. Many times, the reward of working a deep, dark pool is the insights it gives you into the behavior of fish. Once you learn these lessons, you can apply them to the next pool you fish and get into more trout--and more memories--quicker than before.

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