Rig components, and what each one is for

EVERY COMPONENT ON A RIG IS EITHER SOLVING A PROBLEM OR ADDING A FAILURE POINT, AND THERE IS NO THIRD CATEGORY.

SWIVELS exist to stop rotation travelling up the line. A spinning lure, a bait revolving in current, or a fixed-spool retrieve all put twist in, and twist accumulates into a line that coils on itself and casts badly. A swivel is a bearing: if it does not turn freely under load it is doing nothing but adding two knots. A rolling swivel handles load better than a barrel; a three-way is a junction rather than a bearing.

BEADS do two jobs and are frequently used for a third that does not exist. They protect a knot from being battered by a sliding weight, and they act as a stop or a buffer between hard components. They are also sold as attractors, and the evidence that a coloured bead on a sea rig attracts fish is far weaker than the confidence with which it is asserted.

CLIPS AND LINKS let components be changed without retying. That is a real convenience and a real risk: a clip is a mechanical connection with a spring, and it can open under load or be forced open by a lever action against structure. Where a clip fails, everything below it is lost.

BOOMS hold a hooklength away from the main line. Their entire purpose is to prevent tangling during the cast and in current, and they are worth their bulk when a rig is being cast hard or fished in flow, and dead weight when it is not.

CRIMPS join heavy monofilament or wire that cannot be knotted usefully. A crimp must match the material's diameter and be closed with the correct tool. A crimp closed with pliers is a crimp that has either cut the line or failed to grip it, and both fail under load without warning.

SLEEVES AND TUBING protect line from abrasion at a specific point — against a lead's edge, against a fish's flank — and shield a knot. They also swell, grip and stop a safety release working, so they are checked rather than trusted.

STOPS, whether rubber, silicone or knotted line, set the position of something that would otherwise slide. Their failure mode is quiet: a stop that has crept means the bait is not where you believe it is.

THE TEST TO APPLY TO ANY RIG YOU DID NOT DESIGN: name what each component is for. If a component's job cannot be stated, remove it and see whether anything gets worse. Rigs accumulate components the way documents accumulate clauses, and the accumulated ones are usually the ones that fail.