There are several different types of booms used in sea fishing. The main two types are slider booms which are designed to allow a heavy lead or weight to slide along a line in ledger rigs and stand-off booms which make a snood or hooklength stand away from the rig body and therefore reduce the likelihood of rigs becoming tangled. Booms are generally associated with boat fishing and fishing from rock marks at short range for large species where casting distance is not important.
Stand-off booms were traditionally made from stainless steel wire, with the French boom (pictured right) being a classic design of this type of boom. Stand-off booms are most commonly used by boat anglers in a setup known as a flying collar rig. This is used to get a large jelly or soft plastic lure down into deep water without it becoming tangled during the descent. The boom is attached to the mainline (some anglers tie it on whereas others twist the line around the triangular section of the boom) and the lure is tied to the swivel at the end of the boom, as the diagram of a flying collar rig below shows. This type of setup is popular with anglers fishing from boats over deep-water wrecks or rock marks where large fish are likely to be caught.
French booms and other similar types of metal booms can be small at around 4 – 6 inches (10 – 15cm) in length if they are being used in relatively shallow water, or very long at 15 inches (38cm) if they are being used by boat anglers fishing in very deep water. It is important to include a swivel into the design if there is not one already fitted to the boom as the lure will spin and twist as it is lowered to the seabed which will cause the line to kink and weaken if no swivel is present. A weak link rotten bottom can also be incorporated into flying collar rigs so that only the weight is lost if the rig becomes snagged on the seabed.
While French booms are still the most popular for flying collar rigs they can also be made out of twisted stainless steel wire. Plastic stand-off booms are also available. These are tubular and have the line passed through them, although anglers fishing in the deepest offshore locations and over deep-sea wrecks often avoid these plastic booms as they can bend and become misshapen when being lowered long distances from the surface to the seabed. French booms by Koike in four-inch and six-inch sizes can be bought from Sea Angling Shop from £1.39 per pack by clicking here.
This type of boom is used when making heavy running ledger rigs. They consist of a simple plastic tube (which the line runs through) and a clip which allows weights to be easily attached and detached. When used from the shore they are mostly used by anglers fishing for large species hard fighting species such as conger eels, shark species or skate and large rays. Slider booms come in a range of different sizes, designs and colours with all of the main fishing tackle companies making their own slider booms. Larger slider booms are most often used for boat fishing with those used from the shore generally being 3 – 4cm in length. Slider booms preferred to using a simple swivel as they are less likely to damage line and allow the line to smoothly pass through the boom when a large fish moves off with the bait.
The ledger rig is very simple and consists of the boom being passed through the line and then a swivel and hooklength attached, as the diagram shows. This type of rigs allows a large fish to take the bait into its mouth and move away without feeling resistance with the anglers being alerted to the bite through the audible warning given by the ratchet of the reel. A running ledger rig incorporating a slider boom is an inexpensive way of building a strong and effective rig which can be used to target the largest species found around the British Isles. Cronus Slider Booms can be bought from Sea Angling Shop in packets of two or four from 79p by clicking here.