Contrails Lead To The Fish

…Look Up, Before You Fish

David Hutton, Palmetto Fly N Fish 

update Jan 2022

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Where are the fish? 

As anglers, this is our greatest question - El Numero Uno. 

All the gear, rods, reels, lures and gadgets are worthless if you are, "fishing where the fish aint." 

So fishing success ultimately boils down to one question:

WHERE are they?

Where We Look vs. Where They Are

For most of us, the hopeful answer to "where?" is covered by two words:

"shallow water." 

This means anything from 10 feet to ankle deep. 

Why shallow water?

Well, you can see into shallow water, for one thing; it is familiar, non-threatening. 

Shallow water has visual things you can fish around - weeds, wood, rocks, docks, etc. It isn't vast, and formless, like deeper water.

So....

• We fish towards shore from boats
• We fling lures and flies towards visible, shallow targets and "cover"
• We stay near the shore, and fish features of the shore, like points. 
• If we're fly anglers, we are mostly bound to the shallows by our chosen equipment. 
• If we are gear fishermen, we have an entire fishing industry that caters almost exclusively to shallow water fishing.

And, while we get shut down often enough, we occasionally find fish in the shallows... enough to keep us interested, and make us think they sit by a log all season waiting for us to appear.

However, there's a paradox: the big, adult fish we most often want to catch aren't keen on shallow water. 

They DON'T just set up camp by that log all year.

They also don't like bright light, and they don't like feeling exposed. 

So they live deeper. Usually, in the deepest water in an area. 

But when the weather and water conditions are right, these fish WILL go shallow, which saves the day for us. 

An Indicator for Their Movement

Fish want 3 main things:

• Food
• Protection
• Stable conditions in their environment

Look at that list. Now think about shallow water, with its instability, exposure and limited protection, and bright light. 

Not really their cup of tea, is it?

So, they stay in the safety of the deep, dim water most of time.

But, they have a problem - a lot of their food may be in shallow water.

So they must come there to feed when conditions are right.

When that happens, we say something like, "Man, the bite is on today!"

Yet, we still don't really know what encourages them to be there, and more importantly, just when the big fish will move shallow.

Now, suppose we had one reliable indicator that helped us know when those special fish might be coming in range? 

Well, we do. And you see it all the time, without realizing it.

It is the aircraft contrail.

What Is a Contrail, Anyway?

Most people will read that and say, "Huh? The what - contrail?"

If you are alive today, and not blind, you are likely aware of aircraft contrails; you look up and see them and know an airplane is up there.

But almost no one gives them a second glance.

So, the idea that contrails in the sky can help you catch better fish, well...it sounds crazy.

But stay with me here, and I'll explain.

Contrail (short for "condensation trail")

kŏn′trāl″, noun 

Artificial, line-shaped clouds produced by the hot exhaust from aircraft engines; formed at moist, icy-cold, extreme altitudes above the Earth's surface. 

Hot, hyper-velocity exhaust, comprised primarily of combustion products, and super-heated water vapor, blasts out from the engine. It hits the sub-freezing air at high altitudes, instantly condenses into ice crystals...and forms contrails. 

WWII Bombers With Contrails

But it's the ATMOSPHERIC WATER VAPOR that creates the contrail ice crystals. That is the connection.

Moisture is The Key 

Previously, I mentioned that certain conditions will encourage fish to move shallow. Stable weather is a big one, in large part because stable weather normally allows latent moisture to develop in the atmosphere - the kind of moisture that hangs around.

Therefore, when you see a fat, lingering aircraft contrail, you know one thing immediately: there is a lot of moisture in the air above.

And this atmospheric moisture causes a singular effect that is important to fish...

it reduces the intensity of the sunlight striking the earth and its waters. 

Stratocumulus clouds

Normally, we recognize atmospheric moisture in the form of clouds.

Remember, though, that both clouds and contrails require sufficient atmospheric moisture to form....the kind of moisture that reduces light intensity.

In the contrail, we now have an indicator of this fish-friendly condition. 

The Contrail Rule of Thumb

• When you don't see contrails, or only very small, thin ones, then moisture is low, maximum light intensity is on the water.... fish are likely to stay deeper.
  
  
• When you see thick, long, lingering contrails, you can expect reduced light-intensity, other clouds - and fish may move shallower.
  
  

Short, Thin Contrails..

Atmospheric moisture zilch... maximum light on the water, deeper fish

Long, Lingering Contrail w/Late Day Clouds...

lots of light reducing moisture aloft, fish may move shallow

Why Fish Care

With a couple exceptions, nearly all of the fish we might want to catch are strong sight feeders.

For many fish, particularly gamefish, sight is a primary feeding mechanism. 

This means they need light by which to see.

BUT, they don't like intense light for reasons related to both safety and comfort. 

So, the more moisture in the atmosphere, the less intense is the light that enters the water. 

And this sets up a beneficial condition that may encourage the fish to move shallower.

For example, compare a sparkling bluebird sky to an overcast day, maybe even a bit rainy,....what we call a "dark day," one with reduced light intensity.

We say the pure blue sky is 'good fishin' weather.'

"Launch the boat Mabel - the sky is blue!"

But, have you ever wondered why the "dark days" seem to offer better fishing?

Is it because, with the less intense light afforded by the cloud cover, the fish are more willing to leave the murky depths and move further into the shallows where we mostly fish for them.
I think so.

We like the bright blue sky. But the fish don't.

Summary

If we fished in the very deepest water in an area, more often, we would probably encounter more and better fish.

But for most people, that is uncharted territory -  both literally and figuratively.

They simply aren't schooled in fishing such waters effectively, and their supporting industry almost never promotes that kind of fishing.
So, it's a mystery, and it seems like a waste of time.

They stick to the more shallow depths because that's what they know, that's where they feel comfortable.

Okay, rather than upset that apple cart, we'll roll with it.

Accepting that, we can now rely on an indicator that better fish may be moving into the shallows where we actually fish most of the time...
That indicator? The long, thick lingering contrail in the sky.

These will normally be accompanied by clouds as the day goes on, you can expect reduced light intensity - and perhaps more fish where you mostly cast your lines.

So look up every day.
Watch the contrails.
Track their development over time, and look for patterns.

Then you may soon be saying...

"All right - NOW get out your poppers, boys....look at them contrails!"

Okay, say that and people are gonna reckon you're a kook,...until you catch that whopper!

Thanks for reading and Tight Lines!

David Hutton
Palmetto Fly N Fish
© 2018, 2022 All rights reserved

1. Wikipedia, https://en.wikipedia.org/wiki/Contrail

2. Federal Aviation Administration, "Contrails 101,"

https://www.faa.gov/about/office_org/headquarters_offices/apl/noise_emissions/contrails/

3. "A Primer on Solar Radiation Data," 
https://rredc.nrel.gov/solar/pubs/shining/chap3.html

4. N.A.S.A, "Water Vapor Confirmed as Major Player in Climate Change," 
https://www.nasa.gov/topics/earth/features/vapor_warming.html

5. "The 10 Basic Types of Clouds," https://www.thoughtco.com/types-of-clouds-recognize-in-the-sky-4025569