1 - Take 60-inches or so of clear 60/80lb Sufix Zippy trace line or a similar brand. To one end tie on a Gemini Lead Link.
2 - Now slide on a Breakaway Impact Shield or a Bait Clip adding a bead and crimp above. Crimp the crimp in place leaving about an inch for the shield/bait clip to slide in.
3 - Slide on a 5mm bead, a Fox Pulley Rig Bead or a plain rolling swivel and another 5mm bead.
4 - Leaving about 30-inches of free hook trace form a 6 to 8-inch loop and tie in a double Granny knot to secure the loop.
5 - On to the doubled hook trace slide on an 8mm bead followed by a size 4/0 Mustad Viking 79510 hook. Leaving about 1½-inches for the top hook to slide freely in, tie in another granny knot.
6 - On the single loop below, slide on either a 4/0 or 6/0 Viking 79515 hook by passing the end of the loop through the eye and then down over the hook and pulling tight.
Note: The Pulley Rig Bead is better than a plain swivel as the thin wire of a normal swivel eye will stretch and damage mono line during repeated power casts. The Pulley Rig Bead spreads the load over a wider area avoiding this, plus gives a smoother pulley effect than the plain swivel will.
This double hook gives a stronger biting trace as cod have abrasive mouths, plus it helps protect the crucial hook end from abrasion with rocks when dragging the fish back through rocks and kelp.