Poly-leaders: depth on a floater

What it's for

A tapered leader with a fly line's coating: a supple plastic jacket extruded over a mono core, looped at both ends, made in densities from floating to fast-sink. Looped to a floating line it converts the front few feet to a chosen sink rate in seconds — one spool wallet instead of three spare spools.

The beats

1. 1

   What it is

   A coated, tapered leader — typically 5 or 8 ft — with a factory loop each end. Loop-to-loop onto the fly line, add a short length of tippet to the front, and the taper turns the fly over like the line it's imitating.

2. 2

   The density classes

   Floating, intermediate (~1 in/sec), slow sink (~2 in/sec) and fast sink (~4 in/sec — roughly Di-3/Di-4 territory at the tip). Heavier classes exist in salmon and sea-trout ranges.

3. 3

   What it's for

   Control of the top foot or two: sinking a single fly or small team just under the film, cutting through surface chop, or swinging a salmon fly a little deeper without changing the whole line.

4. 4

   What it is not

   A substitute for a real sinking line. Eight feet of fast-sink leader tips the front down; the floating belly behind it still rides high. When fish are at three metres on a windy drift, it's the Di-5, not a poly.

5. 5

   The change ritual

   Carry the wallet, change by loop-to-loop, keep tippet short (3–4 ft) so the taper's work isn't undone. On salmon rivers the rule of thumb: the colder, higher and faster the water, the quicker the sink rate you loop on.

Common faults

When you'll use it

• One floating line and no spare spools: the cheapest route to near-surface depth control
• Salmon and sea trout: matching sink rate to water height and temperature swing by swing
• Sea-trout dusk fishing when the floating-line takes dry up and the fish drop a foot
• Bridging toward sink-tip fishing before buying a dedicated line

Related

Terms: leader · sink rate · intermediate line