Fly Fisherman Throwback: Cul de Canard Strike Indicators

Editor's note: Flyfisherman.com will periodically be posting articles written and published before the Internet, from the Fly Fisherman magazine print archives. The wit and wisdom from legendary fly-fishing writers like Ernest Schwiebert, Gary LaFontaine, Lefty Kreh, Robert Traver, Dave Whitlock, Al Caucci & Bob Nastasi, Vince Marinaro, Doug Swisher & Carl Richards, Nick Lyons, and many more deserve a second life. These articles are reprinted here exactly as published in their day and may contain information, philosophies, or language that reveals a different time and age. This should be used for historical purposes only.

This article originally appeared in the September 1991 issue of Fly Fisherman magazine. Click here for a PDF of the print version of "Cul de Canard Strike Indicators."

---

Many fly fishers believe strike indicators are a modern angling contrivance. The fact is, however, that for years fly fishers have relied upon visible floating leader attachments to detect unseen strikes. Several early practitioners of the sport have described in books how they used brightly colored high-floating dry flies to improve their ability to recognize subtle underwater takes. They tied a nymph to the end of their tippet, then attached a dry fly somewhere up the leader as a dropper. A slackline cast either upstream or downstream kept both flies drifting naturally with the current. Any deviation in the natural drift speed of the submerged fly was transmitted to the floating fly, which in turn was interpreted by the angler as a strike. The strike indicator allowed visual contact with a sunken imitation, and sometimes a fish would take the artificial on the surface.

I am embarrassed now to admit that for years I self righteously placed strike indicators and those who used them in a distasteful and undesirable category. Now, however, I am unashamed to say I was wrong. After coming to my senses and freeing myself from the longstanding bias, I began to objectively try to assess the pros and cons of strike indicators. By accident I discovered a type of strike indicator that corrects many of the deficiencies I observed in most commercially available products.

When I began experimenting with Cul de Canard, or CDC, feathers, I was totally absorbed in their application to fly tying. The feathers are taken from near the oil gland of a duck. Because a duck's oil gland secretes oil that the duck uses to preen itself, the CDC feathers have a high oil content, which makes them remarkably buoyant. Their construction also helps them float a fly. When I started working with the feathers, I had to determine how much of the feathers to use on a fly. Initially I overdressed my patterns. My first attempts floated much too high and were ineffective on the low-water conditions that prevailed at the time.

The first fly I tried was an emerging pattern intended to be fished low in the film, but it was impossible to make it penetrate the surface. I tried slamming it down on the water but to no avail; the fly would not go under. When I pulled it under water, it quickly popped back to the surface. Until then I had no idea how well CDC floated, and it was obvious that I had used far too much material for the purpose. It occurred to me then, however, that lots of CDC feathers attached to the leader could provide an excellent strike indicator. How to make a CDC strike indicator and attach it to a leader was simple, and the results far exceeded my expectations.

CDC strike indicators are versatile. The weight and bulk of other strike indicators I have tried limit the type of water and fishing conditions in which they can be used effectively. High on the list of advantages I discovered with the CDC indicators is the total absence of splashdown when they are fished in delicate situations. Clear, shallow water invariably means shy trout that spook at the slightest overhead disturbance, and the lack of a splashdown improves the fly presentation.

One of the most deadly techniques for fishing spring creeks is to fish small nymphs, larvae, or pupae close to a strike indicator. Small CDC strike indicators can be easily attached directly to the tippet at whatever distance from the fly you choose for the situation. The buoyant and nearly weightless nature of CDC allows detection of the most subtle take as well as efficiently controlling the fly depth. Gently presented, CDC strike indicators seldom spook fish and can be extremely helpful when you are fishing hard-to-see emergers or extremely small drys.

CDC strike indicators also do not interfere with casting. The absence of "hinging" permits longer casts than are possible with foam or cork indicators. I found the CDC indicators to work extremely well when float-tube fishing on stillwater. Cruising lake fish can be difficult to approach, and casts of 60 feet or more are often required to get the fly in front of them. Deep-dwelling trout are nervous when feeding on or near the surface. Twitching the fly and a subtle retrieve are two techniques that are often needed to evoke a strike. CDC indicators offer little resistance on the water, which minimizes surface disturbances and "tracking" that can send shy surface cruisers plunging back into the depths.

Because CDC strike indicators are light, they can also be larger. Large indicators using CDC feathers dyed fluorescent red or green are highly visible on choppy water, especially in poor light conditions. Unlike flies that are tied with CDC feathers, CDC strike indicators are not subjected to the slimy juices and acids of a trout's mouth. Prolonged use can result in the eventual saturation of the indicator, but it can easily be blotted dry or replaced with a fresh one. If a large indicator proves unsatisfactory for the situation, it can be reduced to the right size simply by trimming it down with scissors or nippers. This adjustability factor adds to the versatility of CDC indicators and can save precious fishing time by eliminating the need to change indicators when you move from fast heavy currents to gentler waters.

CDC indicators are a little more expensive, due to the cost of the material and the fact that they are made by hand, but they can be reused from trip to trip.

Avoid using fly floatant on CDC flies or strike indicators. Some floatants can destroy the natural buoyancy of the CDC feathers and make them sink like a rock.

I use red indicators on bright days and green when the light is poor, as in the evening or when the sky is overcast. On spring creeks or tailwaters that receive heavy angling pressure, trout are sometimes spooked by the unnatural char­ acter of fluorescent materials, so I sometimes use a white indicator. This may mean sacrificing some visibility, but it doesn't alarm wary fish. Use white CDC strike indicators when trout seem overly sensitive to conventional colors.

Tie a small indicator on a #10 hook, using two pairs of feathers (4 total), for an indicator that is 1/4 inch long (1/8-inch shank length). Tie a medium indicator on a #8 hook, using two pairs of feathers (4 total), for an indicator that is 1/2 inch long (3/16-inch shank length). Tie large indicators on #6 hooks, using four pairs of CDC feathers (8 total), for an indicator that is 3/4 inch long (1/4-inch shank length).

Tying CDC Strike Indicators

1. Place a light-wire ring-eye hook in the vise and cover the center of the hook shank with tight turns of tying thread. Arrange the CDC feathers in matched pairs. Tie in half of the CDC pairs on each side of the hook shank at the center of the thread-covered portion. The tips of the feathers should extend away from the hook eye and flair away from the shank.

2. Pull the feather butts back over the initial tie-down area and secure them with three turns of thread.

3. Cover the tie-down area with tight turns of thread to form a neat head, and whip-finish. Trim the CDC butts to within one-half the length of the feather portion of the indicator. Remove the indicator from the vise and use wire cutters to cut away the hook bend and the uncovered portion of the hook shank, taking care not to cut the thread wraps or the CDC feathers. Apply an appropriate color of fluorescent lacquer to the head. Variations in size, color, or method of construction can be made to suit your needs.

Attaching CDC Strike Indicators

Most types of strike indicators have drawbacks in the way they are connected to the leader. Some do not stay in position; others are difficult to cast. Still others sometimes fall off the leader.

Ring-eye CDC strike indicators can be attached so that they stay in position. They work best on knotless tapered leaders. Here are three ways to attach the indicator.

1. Pass the tippet end of the leader through the eye of the indicator and secure the indicator in place by tying a simple double overhand knot and pulling it tight. Move the indicator by loosening the knot, sliding the indicator up or down the leader, and then tightening the knot at the desired location.

2. Fold the leader where you want to attach the indicator and pass the folded leader through the eye of the indicator. Then pass the indicator through the loop that forms, and draw the leader tight. This attachment is the easiest to adjust.

3. For a more permanent indicator attachment, use the same method many fly fishers use to attach a dropper fly. Cut the leader where you want to locate the strike indicator. Reconnect the leader with a blood knot, leaving the heaviest tag end three to four inches long. Attach the indicator to the heavy tag end with a clinch knot.

CDC Strike Indicators

• HOOK: Lightest ring-eye hook possible, #6 to #10.
• THREAD: White, light olive, or pink 6/0 Fly Master.
• FEATHERS: Matched pairs of white, fluorescent green, or fluorescent red CDC feathers.
• HEAD: Thread shaped neatly and coated with fluorescent lacquer to match.

---

Rene Harrop is a professional fly tier from St. Anthony, Idaho.

---