I fish a lot of tidal ledges for cod around the Welsh coast, and fresh crab is one of my go-to baits when I want to put a reliable, natural scent in front of bigger, wary fish. Over the years I've settled on a simple, sturdy rig that presents crab well, copes with snaggy ledges and gives me decent hookups without constantly finding my traces shredded by sharp rocks. Below I walk you through the rig I use step-by-step, why each component matters, and a few practical tips for baiting, casting and fishing the tides.

Why fresh crab for cod on ledges?

Crab is a high-value natural bait: it smells and looks like what cod eat and it stays on the hook well when prepared correctly. On tidal ledges, cod often patrol close to structure and take short, deliberate bites — a bulky crab strip or whole crab claw gives a good target and holds together when fish try to spit the bait. I prefer fresh crab when I can get it; frozen can work but lacks the same scent trail.

What I carry in my rig kit

These are the components I reach for most days. I’ve tried many brands; I mention a few that have proved reliable:

  • Mainline: 15–20lb braid (I use 15lb PE for better casting and feel)
  • Shockleader/Topshot: 30–40lb mono or flourocarbon, 1.5–2.5m long
  • Trace material: 40–60lb flourocarbon or mono for abrasion resistance
  • Hooks: 3/0 to 5/0 wide-gape sea hooks (Gamakatsu and Mustad are my go-tos)
  • Feeders/weights: 3–6oz seaside lead (running ledger), or a heavy breakaway lead if fishing very snaggy ground
  • Beads and swivels: size-appropriate ball-bearing swivels, 4–6mm plastic beads
  • Shock bead: to protect knots under heavy impact
  • Baiting needles and elastic: for holding crab strips or securing claws
  • Wire trace (optional): 20–30lb stainless steel for toothy areas where pollack/bass may bite traces

    • Rig design: running ledger with heavy trace

    For tidal ledges I favour a running ledger rig with a fairly heavy, short trace. The running ledger allows the fish to take the bait and run without feeling the full weight of the sinker — that reduces dropped baits and improves hookups. The short, strong trace resists abrasion from rocks and gives a solid connection to a good hookset.

    My standard dimensions:

    Mainline 15–20lb braid
    Shockleader 30–40lb mono/flouro, 1.5–2.5m
    Running trace length 35–60cm of 40–60lb flouro/mono
    Hook size 3/0–5/0 wide-gape sea hook
    Sinker weight 3–6oz depending on wind/tide

    Step-by-step build

    Follow these steps on the bank. I tie everything before I head down to the edge so I can change quickly between spots.

  • Tie your mainline to a running ledger swivel (a small loop or ring). I use a small ball-bearing swivel with a ring or a running loop rigged through a bead — either way the sinker must slide freely.
  • From the swivel, run your mainline through a shock bead and onto the shockleader. Join braid to shockleader with a strong knot — I use a double uni or FG knot if you’re confident with it. The shockleader protects the braid from abrasion and gives a softer stop on the reel.
  • At the end of the shockleader attach another swivel to act as the running connection for your trace. This also prevents twist transferring down to the mainline.
  • Tie your trace to the swivel with a loop-to-loop or a strengthened improved clinch if space is tight. Keep the trace short — 35–60cm — because on ledges you want the hook and bait close to the sinker for better presentation and fewer snags.
  • Attach your hook to the trace with a snell knot or a turned-down knot. A snell gives a good straight pull and helps the hook turn on the bite.
  • Slide on a bead between the trace swivel and trace knot if you want to protect the knot from the sinker ring. Use a shock bead at the mainline-shockleader join to protect against shock from casting heavy leads.

    • Baiting the hook with fresh crab

    How you present the crab matters. I like two approaches depending on the size of cod I’m targeting:

  • Whole crab or large claw: Leave the shell on the claw for resilience. Hook through the base of the claw into the body meat so the claw dangles naturally. Make sure the hook point is exposed or just barely covered so you get a solid hook-up.
  • Crab strips (for smaller hooks or to bulk up a bait): Remove the shell and cut firm strips from the body. Thread several strips onto the hook so they sit as a compact bundle — this keeps shape and provides scent. I use bait elastic looped around the shank to hold strips in place during the cast.

    • Tip: If the crab is particularly soft, quick-freeze it slightly for 20–30 minutes to firm it up. That makes casting and hooking easier without killing the scent.

    Casting and fishing tactics on a tidal ledge

    Ledge fishing is about reading the water. I target edges where the flat runs into deeper gutters or where the tide pushes bait along the rockwork. I cast just beyond the line where I expect cod to be sitting and let the rig settle — you want the sinker to anchor in the rough and the bait to be presented in the water column above.

  • Use enough weight to anchor in the flow. A 3oz may be fine on gentle tides; I step up to 5–6oz when tides are ripping or when I need the sinker to bite into a wrinkled surface.
  • Keep the rod tip low and watch the line for subtle ticks. Cod takes on ledges are often slow pulls or a short lift. I lift the rod firmly when I see a steady pull rather than a single twitch.
  • Change positions if you get no interest after an hour. Tide, wind and bait movement change the holding spots quickly.

    • Handling and fish care

    I always handle cod with care — wet hands or a wet glove, support the fish horizontally and remove the hook quickly with pliers. If you plan to release, aim for quick, shallow hook extraction. Large cod can be heavy on ledges, so have a landing net or a large unhooking mat ready if you expect a big fish.

    Common problems and fixes

  • Bait blowing off on the cast: reduce cast power, firm the crab a little in the freezer or use a bait elastic to secure.
  • Constant snags: shorten the trace and increase weight so the sinker grips better. Switch to a breakaway lead if you’re losing too many sinkers.
  • Trace being bitten through: upgrade to wire or run a short wire leader of 20–30lb between hook and flourocarbon trace.

    • Fishing crab on tidal ledges rewards patience and a bit of local knowledge — knowing where the current creates ambush points is as important as the rig itself. My running ledger with a short, heavy trace and a well-secured crab bait has put me on some of my best cod from Welsh ledges. If you want, I can post photos of my knotwork and baiting steps next time I’m out so you can see exactly how I set things up.