Not a main line — a short bite trace of single-strand or multi-strand wire that toothy fish can't cut through. Essential for mackerel, sharks, and barracuda.
When to use it
Toothy fish (kingfish, mackerel, barracuda, sharks)
Trolling for cutters
Anywhere teeth sever mono/fluoro
Strengths
Bite-proof against teeth
Thin single-strand is nearly invisible in the water
Weaknesses
Kinks (single strand) and can spook wary fish
Requires special connections (haywire twist / crimps)
Key facts
Best species: King mackerel, Spanish mackerel, barracuda, sharks
Underwater visibility: Low (dark coffee color) but stiffer than mono
Stretch: None
Abrasion resistance: Bite-proof
Casting: N/A (short trace)
Knot notes: Use a Haywire Twist (single strand) or crimps (cable)
