In this lesson, we will go into specific tips that will help when you’re scouting for MONSTER trout. I would like to start with what you need to know before you even get to the water.


In this lesson, we will go into specific tips that will help when you’re scouting for MONSTER trout. I would like to start with what you need to know before you even get to the water. I’m not talking about how to cast, or which flies to use. You can find these lessons in the beginner and intermediate sections of the Drifthook Members Portal. In the advanced series, we will be diving into specific scenarios to help you land MONSTER trout, and the first thing you need to learn is the species you’re hunting


So, what can a trout see? How far can he see? And how does this affect how we hunt them? When light enters water, it is refracted. To understand how a trout sees, you must first understand refraction. Refraction of light is exactly 97 degrees wide. When light hits water from side to side, it is refracted into a cone that is exactly 2.26 times the depth that the trout is in. I know… your mind is blown.

But check out this diagram. As we see here, if a trout is 1 foot deep, it can only see 11 inches in diameter. So, in shallow waters, fish can only see in a very small window.If a trout is 6 feet deep, it has a window of 4.56 feet.

The closer the object is to the center of the cone, the more in focus it appears. Objects directly above or towards the inside portion of the viewing portal are more in focus, while the objects towards the edge are blurry and smaller in perspective. Because the eyes of a fish are located on each side of the head, this opens up a blind spot for the trout, 30 degrees directly behind them.

What can we learn from how a trout sees the world?

Outside the cone of vision, the trout cannot see you. But when you’re inside the cone, movements magnify in speed. The best way to approach a fish is in his blind spot and stay away from the blind spot. This includes your line, rod tip, or for you tall guys, even you. Don’t forget about your shadow. If the sun is behind you, work with it so you aren’t casting a shadow that spooks the trout.

What about color? Can fish detect color?

Trout have been proven to have color vision, and unlike humans, they have four cone receptors versus our three. The fourth can pick up ultraviolet rays, probably for tracking polarized light for finding spawning grounds. (pretty cool!)

But just as light is refracted by water, so is the clarity of color. So, the clarity of the water also helps determine the end result of what that trout is seeing.

Have you ever had a trout come up to your fly, and then as soon as you thought it was going to take your fly, it turns around and goes back to its holding ground?

This is most likely because the shape matched what the trout has been feeding on, but then they didn’t like the color when it approached. Try casting again and if you get the same result, swap out your fly to the same pattern but with a slightly different color.

Knowing that trout can see color also helps us decide on what color of clothing to wear when heading out on our fishing trip.

The rule is, try to match your surroundings. If the sky is bright blue, wear lighter colors to match the sky. If you’re in a canyon with dark backgrounds, pick grays and browns to match your surroundings.


Sound travels up to five times faster and farther in water than it does through the air. Have you ever heard the sound of a whale on the National Geographic channel? Some of their frequencies have been tested to travel over 10,000 miles under the water.

Trout don’t actually have ears like humans, but they do have organs that “feel sound.” They have two lateral lines on each side of their body that allow them to detect vibrations—like our ears do for us.

So I know that we have gone into depth about what a fish can see, but don’t forget about what they can hear. You are more likely to spook a fish by tromping in the water before you even get a chance to spook it with your line. Trout typically pick up any sound that is louder than its environment. In areas where the water is calmer and deeper, sound travels faster, so you will have to approach with more caution.

Shallower water, moving water, ripples, or rapids will help hide movement. Even rain on water will help cancel out any unnatural sound. The sound that you create to scare a fish has to be louder than the background environment they’re in.

So take your time, and use sound to your advantage. If you’re trying to imitate a hopper hitting the water, go to town—slap that bug off a bank or rock to mimic a large meal. If you're casting a soft dry into a slow-moving pool, cast at a spot above where you want the fly to land and let it float down into your zone.


Yes smell.

Trout have an amazing sense of smell. A trout’s nose is actually two specific holes called “nares” that they use to sniff out chemicals in the water. It has been tested that fish can use smell to find their way back to the place that they were born. So what does this mean for fly fishers? It means that anything we have on our hands can be transferred to our flies and be a deterrent to the trout.

Sunscreen, hand lotion, tobacco, even bubble gum. But don’t worry, this can be easily fixed. Before casting your flies, grab a little river gunk, cover your hands with it, then rinse them off. This will help eliminate any unnatural odors that will cause the trout to reject your fly.