I have always enjoyed "chucking and ducking" weighted nymphs upstream into a current.  But needing help with strike detection, my nymphing was aided by a hard foam indicator (a bobber!) twisted onto the fly line.

This all changed in the Spring of 2001, when Ed Laine of Charlotte, North Carolina sent me a section of old fly line and a few samples of one-inch indicators made from it.

HOW TO MAKE THEM

Anyone who has stripped insulation from copper wire will be able to visualize the process of making these indicators. 

1. With a single-edge razor, cut the line's vinyl covering without cutting through the nylon core.  It is better to make shallow cuts rather than to cut into the core.  One-inch indicators are about right.  You can always cut them shorter afterwards to suit your needs on the water.  After all, an old fly line will provide a lifetime supply of indicators!
2. Pour a little nail polish remover into a container.  I use a small recycled margarine container. Soak the end of the line for about 10 seconds.  This is usually enough. 
3. Pull the vinyl section off the nylon core, using your thumbnail and fingernail.  (Now you have a great reason to stop biting your fingernails!)

HOW TO FISH THEM

Fishing with these indicators is easy.  Just thread your fly line through one, and slide it up the leader and over a knot to secure it in place.  For upstream fishing I usually place the indicator halfway up the leader.  If I turn around and fish downstream I either leave the indicator as is or slide it a little further up the leader. 

For me, this is a perfect system for fishing Buggers in streams and rivers.  Most people I know fish Buggers either by: (1) casting "across and downstream" or (2) in deep water, casting "across and upstream", to allow the fly to sink a bit before it swings downstream. The fly-line indicator is so thin that it will not interfere with your downstream fishing.  Plus, if you turn around and face upstream it will allow you to dead-drift a weighted Bugger with confidence!

When you first fish it, you will notice something that doesn't happen with foam indicators.  It sinks!  But this is one of its many advantages.  First, you can generally see the indicator even when submerged.  I recommend fluorescent red or orange.  More importantly, because it is strictly an indicator and not a bobber, it allows the fly to tumble along the bottom where the big fish are. 

In darker water and in deep pockets I have lost track of the indicator on occasion.  When that happens I depend on the end of the fly line as my indicator.  This is not always satisfactory, as there can be considerable slack in the leader, between the end of the fly line and the fly, causing strikes to be missed.  It has been suggested that another option is to use two indicators.  I have not experimented with that yet.... But I will. Perhaps two 1/2-inch indicators will do the trick. 

If you are like me you catch many tree fish and frequently get hung up on stream bottoms.  When fishing without an indicator, retrieving your fly can usually be accomplished (on streams and small rivers, anyway) by winding in your line, leader, and tippet until the fly is nestled in the tip-top guide.  Frequently a few shakes will then free the fly.  Fishing with foam indicators is always a hassle because they must be removed first before you can perform the rescue operation described above.  But fly-line indicators are so thin (after all, they are made from fly line) that they wind right up, easily passing through the rod guides.  No more hassle!

WHY USE INDICATORS?

I am a strong believer in strike indicators.  And the fly-line indicator is my favorite style because it is so unobtrusive.  It should help even the best angler pick up more strikes.  The reason for this is that without an indicator all that you can see while nymphing is the fly line tip.  This is too far from the fly!  There is always some slack in the leader.  This means some strikes go undetected, or at the very least the detection is delayed.  With the fly-line indicator set, say, halfway up the leader, slack in the butt half of the leader will not interfere with strike detection because the fly line indicator will move first.  And, it will always move before the end of the fly line moves. 

Give it a try.

--Peter Frailey