Published Apr 12. 2004 - 19 years ago
Updated or edited Nov 26. 2022

Strike Indicator Scientology

Strike indicators aren't just flyfishing bobbers; they do much more, if you know the secrets! Learn how to make and use them from GFF partner Steve Schweitzer.

A full set of strike indicators, using the tying methods below, will last for years. You might as well give some to your friends while you're at it.

I fish strike indicators almost every time I nymph. You might think that's an abolishment to the pure form of flyfishing. Well, it can be if you are using strike indicators merely as a bobber, which isn't a bad reason in itself. But there's so much more they can do!

Fishing strike indicators

Let's start by reviewing three basic ways to use strike indicators.

1. Get Depth-Charged

I use strike indicators to help depth-set my nymph rig. For this reason alone, I want a strike indicator that is easy to move up and down the leader and would keep the depth I prefer. In other words, it won't slip toward the fly every time I cast. I also design my leaders to fit the use of strike indicators. For more on leaders and leader construction, see my article entitled Hyper-Compleat Principles of Leader Design and the downloadable companion software, Leadercalc.

2. Avoid the Vortex

I often use a strike indicator when I dry fly fish over choppy, white water. The indicator helps keep the leader afloat around the butt section, avoiding that treacherous leader dunking that fast water can present. It also allows me to more easily locate my dry fly in fast, white, roily water. I've found that leaders with smaller butt sections and longer whispy tippets are best for fishing this type of water.

3. "See" the Fish Attack

It's no secret that strike indicators are the flyfisherman's version of a panfish bobber. But how you use it will make or break your success. Simply attaching a big ball of brightly colored yarn to your leader isn't
going to make you a better nymph fisherman. You must learn where to place the strike indicator and how to read its' movement to help you "see" the fish strike.

Strike Indicator Placement

Steve's Strike Indicator Placement
= Fishing Depth + 2 or 3 feet

Take two basic things into consideration when choosing where to place a strike indicator. First, the depth at which fish are feeding and secondly, the speed of the current. The faster the current, the higher to place the indicator. The deeper the fish, the higher to place the indicator. This only makes sense. I do not believe in nor follow the commonly reiterated rule-of-thumb where the leader must be 2x-3x as long as the depth in which you fish. This is absurd...if I am fishing a deep pocket of 5 feet or so with a moderate current, just where do you think your fly will drift using a 15-foot leader? Your guess is as good as mine! You must gain control of a nymph rig to be effective; a well-placed strike indicator will help you do that. I estimate the depth to fish, add 2 or 3 feet and place the indicator on the leader at that point. Then, I use a combination of weighted flies and split-shot to get the leader to sink faster.

Reading Strike Indicator Movement

Attaching a Strike Indicator:
Form a Loop-to-Loop Connection

Form a loop with the butt section of the leader. Insert the loop through the O-ring on the indicator, bringing the loop over and around the top of the yarn. Pull the loop taught against the O-ring and throat of the indicator. More on this issue...

Concentrate on two movements to distinguish being snagged from "seeing" a fish take. A snag looks oh-so-close to a real take. And to make things worse, subtle takes are not very distinguishable from touching the bottom. However, being snagged stops the strike indicator from moving, whereas a fish take many times makes the indicator move in an abnormal direction. This distinction is ever-so subtle and takes time on the water to distinguish. Another way to tell a real take is the angle in which the indicator goes under. A real take will oftentimes go more directly downward, whereas being snagged/dragged will drag the indicator backwards, against the flow of water, at a subtle angle. Just practice and play with the position of the indicator to get the right depth...and, learn to spot the flash of a feeding fish's mouth. If you fish to that sentinel, you won't need indicators!

Orvis' Marabou Hair or McFlyFoam's McFlylon is the author's two favorite choices for making strike indicators.

Making strike indicators

Yarn selection

Not all yarn is created equal. Don't bother with wool, cotton or most soft acrylic yarns...unless of course you like making pretty sponges. Some wirey acrylic yarn is marginally OK, but most is soft and merely unacceptable. The best yarn to use is poly yarn. There are many different deniers of poly yarn, some unsuitably
heavy for making strike indicators. I have found that craft poly yarn has the right denier, or fiber thickness, to help trap air and resist trapping water, ill-reported as "absorbing" water. Taking the yarn concept even one step further reveals a few flytying products are actually excellent materials to make indicators. I prefer Orvis' Marabou Hair or McFlylon as the all-around best material in which to craft an indicator. The denier is perfect, the density of the fibers is perfect and the fibers are irregularly crinkled, breaking up the uniformity in which straight hanks of poly or yarn may have.

Discussion of color choice

I prefer strike indicators that mimic what floats down the river naturally: moss, weeds, leaves, etc. I have seen too many times fish deliberately moving out of the path of my rig well before the leader gets into sight of the fish. After changing to smaller tippet and ensuring a drag-free drift, I surmised my big fuzzy fluorescent pink glo-bug yarn strike indicator actually acted as a beacon that something unnatural was about to come. I don't use bright colored strike indicators any more. So, choosing the colors for strike indicator yarn hasn't been difficult. I prefer a mix of grey and bright green to mimic most of the plant debris that floats down rivers I fish in the Rockies. I know others that prefer tan, brown or dark olive, but those can be more difficult to see in marginal light.

O-rings are commonly found in any hardware store and are the "glue" that holds a strike indicator together.

Notice the fraying yarn clogging the loop. This fraying will increase over time, preventing prolonged use of an indicator. Surgical glove rubber will solve this problem.

Making night-vision indicators

There are times, however, where adding some fluorescent colored yarn makes perfect sense. Twilight hours either in the morning or late in the evening prove to be the most difficult times to see an indicator. Adding a bright color in the middle of the indicator will help you see the drift, but will hide the "beacon" from the fish. I have found using yellow or orange yarn is great for advancing morning light or shaded fishing runs while orange or pink is great for declining evening light. You'll notice I like orange yarn to cover all lighting situations.

Choosing o-rings

The O-ring is essentially the "glue" that holds the whole contraption together and keeps the indicator on the leader. With that said, it's essential to pick the right size. An O-ring that is too small will lock up on the leader and disallow moving the indicator around. An O-ring that is too big will slide too easily and may force the leader to fold over on itself. Look for O-rings between 5/16" OD (~8mm) for smaller indicators and 3/8" (~10mm) for larger indicators. Any hardware or home improvement store will carry O-rings this small.

One other key ingredient

A Global Fly Fisher EXCLUSIVE!

Developed in the secret Fly Flyfishing Labs at The Global FlyFisher!

You'll notice that strike indicators will fray over time, almost to the point of becoming unuseful. The picture to the right displays how used indicators (L:tied with thread, no O-ring; R: tied with O-ring, no yarn protection) will fray with just a few times of use. Enter the surgical glove. With just a small slip of elastic rubber snipped from a surgical glove, you can craft a protective cover for the yarn. This little trick will make your indicators last almost all fishing season. You most likely will never see this feature in any flyshop strike indicator. I have also found that it helps prevent the indicator from slipping on the leader. You'll find that taking a moment to tie in this extra material will pay off many times over.

The materials are simple. Yarn, elastic rubber and an O-ring (not pictured).
A slip of surgical glove rubber, an O-ring, two strands of Orvis Marabou Hair, some twilight vision yarn and sturdy 6/0 thread.

The Detailed Steps

Follow the steps below to create your own durable strike indicator. Prep the strike indicator yarn by cutting approximately 9" (23cm) lengths of yarn. You'll need two 9" hanks for each strike indicator, plus a 2" strip of visible yarn if you choose to make your strike indicator more visible in twilight situations. For the two main 9" hanks of yarn, use the same color or mix colors as shown in the tying steps.




Using the 9" hanks of yarn, double and fold over twice. Cut a 2" section of bright yarn, if a twilight indicator is to be tied. Lay the bright yarn on top of the folded sections. Slide an O-ring over the jaws of a pair of forceps. Clip and secure the folded prepared sections of yarn at one end.




Slide the O-ring off the forceps. and to the middle of the folded yarn. Now, unclip the forceps. and fold the yarn over, hinging on the O-ring. ENSURE THE BRIGHT YARN IS IN THE MIDDLE of the folded yarn bunch. Re-clip the forceps. above the O-ring to hold everything in place. Slip a 2" piece of surgical glove rubber through the O-ring, centered.




Hold the ends of the rubber slip back towards the top of the indicator yarn. HINT: if you find this step difficult, you may find it easier to apply a few wraps of thread around the yarn above the O-ring (as pictured in Step 8) before adding the slip of rubber. Be generous when wrapping the thread around the yarn and slip of rubber. Tie off as close to the O-ring as possible. Whip finish and apply a drop of tying cement if it makes you feel more secure about the wrap./td>

The nearly-finished strike indicator should look something like this. Stretch the tag ends of the rubber slip and trim to the wraps of tying thread.




Firmly grab the ends of the yarn and pinch in a tight, compact fashion. Trim the yarn to remove the folded loop tops and to even things out. A finished strike indicator (with twilight vision yarn) is ready to fish! Notice how the brightly colored yarn cannot be seen by the fish when the strike indicator is floating in the water, but can be seen by you!

HINT: Dab a few drops of dry fly floatant or rub tying wax on the indicator to help it float higher and longer without sinking.

Attaching the indicator to the leader

A couple of questions ticked in. The subject is covered in the article, but a GFF visitor supplied an excellent answer.

Drawing By Martin Joergensen


by Arthur Smith
The article entitled "Strike Indicator Scientology" is exceptional, I really appreciate Steve Schweitzer and GFF sharing this valuable information. Also, I've never fished these type of indicators and am almost embarrassed to ask how they are fixed to the leader? Adding this information to the article would really be the icing on the cake. Tight Lines...


by Michael Ericsson
Very green angler wondering how to attach o-ring style strike indicators to my leader?


by Kieth
If you have ever done a loop to loop with butt section and leader to from a square knot this is essentially the same thing. Simply form a loop in your leader by doubling the line on itself take the strike indicator with the o-ring facing up and slide the o-ring over the loop in your leader in the general area you would like the indicator positioned. Now flip the indicator through the leader and pull. The leader and the o-ring should be looped to looped and form a square knot. You can slide the indicator up and down depending on where you would like it. If you are using the polypro yarn type of indicator you should consider using some gink (a dry fly paste called Gehrkes Gink) this will help the yarn float.
Good luck,
World Wide Angler Fly Shop
Anchorage, Alaska



Martin Joergensen's picture

sebastiaan, The p...


The precise size of the ring is not really important. 8 millimeters is just an approximate size, so whatever you can find in that range will do fine.


Is the outside diame...

Is the outside diameter 8mm or the diameter at the inside of the o-ring 8mm?

Excellent article an...

Excellent article and website. I see that some of the commercial versions use closed cell foam instead of yarn. Is this material available pre-cut at craft stores or must it be prepared as suggested by Robert Olsen in a previous post? The foam seems to offer the advantage of being high floating without treatment but cutting the sheets into thin strips as small a 1/16" would be difficult. Thanks.

You are DA best Than...

You are DA best Thank you

They a super indicat...

They a super indicator. They are fun and easy to make.They are very good to use for bluegill fishing as well.
Thank you so much.

Awesome website........

Awesome website.....These indicators are the best thing since pre-sliced bread. At least I think so.!

I hired a guide for ...

I hired a guide for the San Juan last year. We went out in his boat. He had a bunch of polypropylene rope in it. I figured it was for the anchor. Nope. He said "I'm going to make some strike indicators" and while we were on the river, he hacked off a piece of rope, went through a bunch of steps of rubbing it on a piece of velcro to frizz it out, tied it in some fashion to the leader, and there we were! We fished all day with those indicators.

I'm glad I came across this article because I couldn't remember how to tie it on, and your O-ring solution looks good. I'm going to give it a try and fish the Frying Pan, colorado next week.

I want to make a few...

I want to make a few of them up using your method but I can't get any Orvis Marabou hair (I don't think they make it anymore?). Whats the best alternative?

tight lines

nice indicators real...

nice indicators really like them is it possible to buy some ov these

Great article! Thoug...

Great article! Thought I would pass along a tip for carrying your strike indicators. A couple of years ago I tried some strike indicators that were small circles of foam with a hole in the middle (looked like a washer basically). They were yellow on one side and black on the other. They were OK but not great as indicators as it was hard to get them to consistently land with the visible (yellow) side up. But they did come on a ring clip that is very handy for holding an assortment of indicators. You could use a notebook ring from any office supply store. It holds a bunch of assorted indicators and I clip mine on my lanyard. Works great.

paulmsheldon-at-yaho..., mate what a great tip. i was just lamenting the fact that i would have to wait until tomorrow to go buy some O-rings when low and behold i came across your gem. My daughter has just 'lost" half a packet of 1/4 inch orthodontic elastics.

Here is another alte...

Here is another alternative to the McFlylon material. Go to your local craft store where you can purchase flat sheets of 1/16" colored foam. Using a single razor blade and a ruler cut strips 1/16" by 8" long fold them down to 2" pull them through the o-ring and tie them down with your instructions above and they work great. You can even buy two colors and make them more visable in the later evening. I used the bright yellow and orange colors. I also tested these indicators buy attaching different weighted nymphs to them then I put them in a bowl of water after 12 hour of constant soaking they were still floating Great. The other thing I found is that they are also real easy to trim on the river with your tippet snips if you want to make them smaller so don't cut them too short when making them.

I use the Fish Pimps...

I use the Fish Pimps and absolutely love them. They do not interfere in either forward or back casting!

A suggestion on keep...

A suggestion on keeping the indicator in place is to pass the loop thru the O-ring and then twist the loop one time before placing it over the indicator. This has worked great for me. Love this site. Keep it oming...

Instead of 'O' rings...

Instead of 'O' rings, use orthodontic elastics (1/4", 5/16', 3/8"). I find these better than the "O" ring as well as eliminating the sliding problem. Additionally, it keeps me thinking of the stream, when I'm working in my office.

Great article. I ...

Great article.

I too used to think that fishing indicators was a monkeys game but I now know it makes all the difference!

I want to make a few of them up using your method but I can't get any Orvis Marabou hair (I don't think they make it anymore?). Whats the best alternative?


Here's a site for al...

Here's a site for all poly cord for strike indicators. They have about 20 color plus one cord that glows in the dark.You get 50 yards for about $4.00 bucks. then go to Bonnie Braid. I also use the O rings from Harbour Freight and then use the small rubber band from the orthodontist to hold it together...Good luck

About 15 years ago a...

About 15 years ago a guide at Lee's Ferry fluffed up his strike indicators by combing the yarn with the rigid side of velcro. Worked so good I put the velcro on the end of 1/4" copper pipe about 3" long to make a velcro comb.

I used to think putt...

I used to think putting a sight bob on was just monkey fishing an absolute disgrace, but over the years i have to admit i do use them on still waters where i have taken many fish on the drifting wind which i find aceptable a certain times, my good friend Peter Whittle showed me that. But to go and cast out and just sit their thats monkey fishing lads.

I built a bunch of t...

I built a bunch of these indicators using strips of craft foam (instead of yarn) and a box of "O" rings in different sizes I got a Harbor Freight for about $4. I still prefer red, green, pink Lil' Corkys for indicators. I cut a slot thru the side with a hobby saw so I can put them on the leader or move them past tippet knots without removing my fly. I peg them in place with pieces of round wooden toothpicks and they stay put pretty well. Two drawbacks; when my casting gets lazy, the leader can get stuck on the toothpick if it isn't trimmed short. I've also had trout hit the indicator instead of the nymph. I plan to start coloring the bottoms so they're less attractive.

Great article. The ...

Great article. The polypro yarn is sometimes difficult to find. You can get it one-yard pieces or macrame rope @ $.40 each, at "", just look under "macrame cord", then "fly fishing cord".

Tight lines

Great Article on Str...

Great Article on Strike Indicators. I enjoy fishing rivers and will definitely tie some of your indicators and try them on some of west coast rivers.

I prepare the newsletter for a small fly fishing club of about 30 members. Total distribution is to about 40 people.

May I have permission to reprint your article. I will make sure that the author and your website receive all the required credits.

Thank you

Sandy McKinlay
Osprey Flyfishers of BC

Operating rooms are ...

Operating rooms are full of great stuff for tying material. Foley catheters (yep...the things that they snake into your baldder) make great O rings....just chop them into short little rings. Different diameters too. If you're the sensitive type you can soak them in a lysol solution...or just use any rubber or plastic tube you find around the house. A lot cheaper than o rings too

Good job. Any ideas ...

Good job. Any ideas how to make a right angle on a leader where indicator conected? (90* angle let fly sink more faster)

Great web-site thank...

Great web-site thanks for all the tips. What’s the difference between McFlylon, and McFlyfoam, if any? Thanks Ron

I like your article ...

I like your article and made a few indicators this week with materials I had on hand. I used some EP Fibers 3-D (Enrico Puglisi) and tried one at a neighbor's pond on bream. I coated it with Gink dry fly dressing. Worked great but I'm looking forward to seeing how the EP does all day on a river next weekend. I had some latex gloves on hand because they are a great substitute when making Condom Worms.

Thanks for the site!

hi there i really li...

hi there i really like story and i live in NZ.And am wondering where i could buy that MCFLYLON stuff. THANKS.

Great info on making...

Great info on making your own strike indicator's. I have been making my own now for a few years and have been using "macrame yarn". I have found this stuff at craft shops in all sorts of colors and does it ever float well.The tip about the latex strip is fantastic. Instead of using fly floatant for that extra boost I have found a product called "Albolene" It is a "make-up remover" with a large content of parafin wax. I'm sure you could float a lug nut with this stuff!. It is available at Walgreens Drug Stores. I have had a container of this stuff for 3 years now and I'm only about half way through it. It also works well on large dries such as hoppers stimulators etc. Not very good for small stuff. $7.00 gets you 12oz. Another indispensible tool for my yarn indicators is a stiff comb to "pimp-up" the yarn after it starts to mat out.
Another indicator that I have been using might be of interest to some of your readers. Try using a "Water Balloon". Yup I said water balloon!. A friend who guides on the Green River suggested it to me. I guide on the Bow River here in Alberta myself. Water balloons are quite small- about an inch and a half un-inflated. Blow it up to the size of your thumb nail and attach it snug to your leader with 2 overhand knots, one above the other.Tie it around your leader just like you are tying off a balloon You will be able to adjust it at anytime and it will never sink. The key is not to make it to big or casting will be an adventure. They come in every available color and are very cheap. Here in Canada $2.00 gets you a 100 of them.Try Walmart type stores.There really is a specific balloon made for filling with water so make sure you get "water balloons". any other is just to big. In order to camoflage the bright colors, once tied on the leader I will take a black permenant marker and cover the bottom of it leaving the top quite visable.. VERY sensitive to anything going on under the water.
Great website. I have found it full of very usefull info and insight so I thought I would share some things I have discovered to be helpfull on the river. Thanks!!

instead of using el...

instead of using elastic rubber ( latex glove ) .
can you substitute the 2" piece you use to go through the
o-ring with vinyl disposable gloves ?
i enjoy the website , its very useful .

Martin Joergensen's picture

Edward, Regarding...


Regarding the position of the indicator and problems with sliding. I have had the same experience a couple of times. Consider passing the top of the indicator twice through the loop. It will give an extra twist, but steady the ring on the line.

I have also used the indicators on knotted leaders where a knot will stop the indicator from sliding.

A smaller O-ring leading to a tighter loop might also do the trick.

Hope this helps.


Everytime I try to u...

Everytime I try to use the "o" ring type indicators, they will travel down the line, i.e. not stay in the original position which negates their critical placement. Any suggestions on how to keep them in their original position?

Steve, Thank you ...


Thank you for your suggestions for indicators. I enjoy making my own indicators and do indeed like your added technique of the latex. I'm always on the lookout for more effective materials to use.

Any updates to add? Have you found any material that is better than the Orvis' Marabou Hair (which I'm not sure they still make) or McFlylon?

Also, as for the twilight yarn element, what is the "best" material to use for that? I see you've used a twisted yarn in the photos.

Thank you.

This is an awesome w...

This is an awesome website! Have you seen the new mini Fish Pimps made by Angling Evolution. I have yet to try them but will in the next couple of days.

Why people hate on indicators.....

It cracks me up when dry fly purists look down on indicator fishing as "bobber" fishing. For that matter dry fly fishing is bobber fishing too except the bobber happens to be a fly!. Its easy to detect a take on a dry fly all you have to do is look!... umm sounds kinda like indicator fishing don't it???;) Truth is that nymphing is very subtle, challenging and rewarding once you get the hang of it. Much more difficult to get the hang of than dry fly fishing in my opinion and just as rewarding to me at least. Actually in many ways more so.


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