Fly line mending in mixed currents: choose the right direction

The short answer

Compare the current carrying the line beside you with the current carrying the fly. If near-side water is faster, it sweeps the line downstream ahead of the fly, so an upstream mend can remove that belly. If the fly is traveling in faster water than the line between you and it, the fly gets ahead and the slower line can hold it back, so a downstream mend may be needed. Mend direction follows the river, not the direction you cast.

Orvis's practitioner video How to mend line when fishing nymphs describes both directions: upstream when the water next to the angler is faster, downstream when the water between the angler and flies is slower. The Orvis Video Pro Tips on mending fly line also shows that a mixed-current drift may need more than one small correction.

Read the line in sections

“Near-side” means the water and line between you and the fly. “Far-side” means the current carrying the fly and the line beyond the seam. The surface may contain several current lanes, so do not assume the entire line is moving as one piece.

1. Watch the fly or indicator beside bubbles, foam, or another visible reference moving in its lane.
2. Notice whether the line between you and that lane is forming a downstream belly, falling behind, or pulling the fly sideways.
3. Identify which section of line crosses the faster current. That is usually the section to reposition.
4. Mend before the line tightens and drags the fly. A late, oversized correction can disturb the very drift you meant to protect.

When faster near-side current sweeps a line belly downstream, lift and move that section upstream. When the fly is riding faster water and the line nearer you lags in slower water, move the slower section downstream so it can keep pace. These are starting directions. Eddies, changing seams, and subsurface flow can alter what the surface line appears to be doing.

Move the line without moving the fly

Lift only enough line to place a new curve in the section that needs correction. Keep the mend's hinge near the current seam, and let the rod tip follow the line rather than sweeping the leader and fly across the water. With an indicator rig, Orvis cautions that moving the indicator also moves the flies, so mend the line with a light touch and preserve the indicator's drift.

A large initial mend can be followed by smaller corrections as the cast moves through different current lanes. If a new seam changes which section is faster, the next correction may point in a different direction. Watch the drift after each mend instead of repeating the same motion by habit.

When a different presentation is cleaner

A mend is not the only way to reduce drag. A shorter cast crosses fewer current lanes. A reach cast places an upstream or downstream line curve in the air before the line lands, so the fly starts with less immediate tension. Orvis discusses reach presentations and line position in a practitioner conversation about drift control. For close nymphing, keeping more line off the surface can reduce the current's pull on it.

A safer bank position can help too. If the shoreline allows, move to firm footing where your cast crosses fewer different currents. Do not enter uncertain or fast water to improve a drift. A simple change of casting angle can be more useful than making repeated corrections from a poor position.

Where this method can fail

The surface current can differ from the current at the fly's depth. A foam patch or line belly is a clue, not a perfect map of the water below. Strong turbulence, obstructions, wind, or a fly that is already swimming across current can make a mend difficult to interpret. In those conditions, simplify the cast or change your angle before changing fly patterns.

A successful mend removes unwanted line tension. It does not prove that the fly is at the right depth, that a fish is present, or that every species will prefer a dead drift. Check current local access and fishing rules before choosing where or how to fish.