The correct way to mend fly line:
I mend my fly line frequently when I’m fly fishing for trout, salmon, smallmouth bass and steelhead. If you think of the word correcting rather then mending you’ll have a better understanding of your goal.
Let’s assume you are fishing a streamer across stream and you would like to have it maintain a broadside appearance to the fish as you strip it across stream. However, the current where your line enters the stream is moving much faster than the line 40 feet out where the streamer is swimming. This produces an unnatural fast action on the fly so you lift your rod high in the air and lay the line well upstream with an exaggerated sweeping motion. However, you must pick up the extra line that occurs with this mend because if the strike comes with all this slack line on the water you probably will not be aware of it and you’ll miss the fish. By picking up the excess line with your line hand you will have a tight line on the fly you can quickly feel the strike and set the hook. The correct mend will help you fish drys, nymphs and streamers more effective.
Listen to my fly fishing podcast “Smallmouth Bass Podcast Part IX on Smallmouth Fly Fishing Streamer Tactics” for more information on mending fly line.