Do strike indicators scare trout?

Strike indicators serve two main purposes. To give a visual clue for when a fish takes the fly, and to control a fly’s maximum depth. To work best at giving a visual clue, they must be clearly visible. But does that visibility scare fish?

Strike indicators can scare trout, but a well-presented one should not. To avoid scaring trout, try and cast the indicator as gently as possible to minimize splashing. Even more importantly, make sure to minimize unnatural ‘drag’ moving the indicator at a faster rate than the trailing fly. Such drag is one of the biggest causes of spooked trout.

Splashing an 1 inch indicator right on top of a trout will likely send it swimmign. But, avoiding such obvious mistakes, the presence of the indicator itself is unlikely to spook many fish. The color of the indicator does not matter too much, ideally it will be floating out of sight anyway.

I quite often have had trout confuse an indicator for food. I have had them raise and eat yarn indicators, and stock trout are even known for grabbing foam balls at times. In this article, I am hoping to argue that the drag caused by an indicator is a much bigger reason for spook trout than trout seeing the indicator itself.

Three reasons why indicators spook trout

  • – The presence of the indicators (including the shadow they might cast)
  • – The splash of the indicator
  • – Drag caused by the indicator

Unnatural drag scares more trout than the appearance of the indicator!

I personally believe drag caused by an indicator is responsible for spooking more trout than the presence or the ‘splash’ of the indicator as it lands.

Let me explain. Imagine you are fishing a small nymph beneath an indicator, you cast it, the nymph sinks and the indicator floats. But the current, or wind on the surface starts to move the indicator, which in turn causes the nymph to drag through the water. This unnatural movement is enough to convince a trout not to strike.

How to reduce the drag caused by an indicator?

It is important to match the size of the indicator with the size of your fly. Fishing a size #22 unweighted nymph then pair it with a few strains of yarn. Dead drifting a heavy tungsten #6 Stone fly then depending on the turbulence of the water, you might be able to get away with a 1/2inch foam ball.

If you are drifting a streamer beneath an indicator, drag is of less concern. That is because streamers represent larger aquatic life that can naturally move against the current. So when drifting large streamers through turbulent runs, even large indicators like a 1” Thingamabobbers might not scare fish.

The aim is to have the nymph control the path of the indicator through the surface and not vice versa. If the indicator is moving the nymph, then you are probably using too large or dominant of an indicator.

My personal preference?

I like to bring a selection of indicators to the river. I use different sizes and styles for different techniques.

In calmer waters, my preference is to always use a dry fly as an indicator. I have had trout raise to inspect indicators, so why not attempt to catch such fish. My favorite flies which I use for indicators are small foam beetles, Parachute Adams, and Stimulators.

When conditions dictate that I need more buoyancy, or if casting a double fly rig becomes too difficult. I usually stick with a yarn or wool indicator. I like wool because it is natural and I can easily add more or less wool based on the weight of the fly I wish to fish. Wool is also very light, that even a big chunk is unlikely to create much drag.

On rare occasions, when the water is too turbulent for wool. I use a foam or cork indicator. There are many great brands but lately, I have been favoring the CorQ indicators from Orvis.

For more information on which indicator to fish where I have written a quick review for the most popular indicators here.

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