The author with a Fiordland groper taken on the rig described in this article.

High-Performance Deepwater Groper Rig

by Allan Burgess

Here is a ‘high performance’ groper rig for those who want a set up that can handle almost anything. It is essentially a very heavy duty Paternoster rig with two droppers. It is a well-tried and tested proven performer on groper in the deepwater trenches off the Banks Peninsula, Fiordland and Kaikoura.

The monofilament used for the mainline and droppers is 230kg (500 lb) breaking strain Shogun from Kilwell Sports. One big advantage of such heavy mono is that it tends to straighten out rather than curling up and tangling. If you drop the completed rig on the deck and then pick it up again you’ll find that it refuses to become tangled. This is a great feature particularly if you are fishing in rough conditions far out at sea. Fewer tangles mean less time spent bent over fixing them and more time spent fishing.

The finished rig curled and held in place with a wire bag tie and then stored in a plastic bag ready for use.

Heavy monofilament also means you stand a reasonable chance of landing other toothy critters like sharks.

The heavy mono prevents barracouta from biting through the rig on the way down. At certain times of the year around some parts of the South Island, notably the Otago coast and Kaikoura, barracouta can be so prolific that it can be almost impossible to get your gear down to the bottom without repeated hits from them. They can bite through lighter mono with ease. This can be a curse if they keep chopping through your rig; not just biting off your hooks but slashing at the swivels as well!

When fishing very deep for groper you need plenty of weight to get your gear down to the bottom. The rig needs to be strong to take the strain of winding up from deep water with perhaps a groper on each hook.

We are using hard clear Leda-Lon nylon tube slides over the 230kg mono droppers protecting them from abrasion.

The top loops are protected with armour spring or plastic tube.

The crane swivels are also used by commercial long-liners. These are slid along the 230kg mainline or “backbone” and crimped into place.

The monofilament droppers are crimped on to the swivels and then the tube passed over the top of the mono. Use rubber tube to slide along the Leda-Lon tube and up over the end of the crane swivel as shown in the picture. This makes the dropper stand out at a right angle from the mainline and so greatly reduces the possibility of a tangle. The soft surgical tube is thick-walled whilst still being soft and supple and easy to push along over the swivel for a good snug fit. You can also use the outer tube from an electrical cable, though you need to have just the right size for a good snug fit. A little dishwashing fluid helps to slide the tube into place.

With one end of the dropper line connected to the crane swivel and the tube covering it the next thing is to push 60mm of 4mm luminous tube over the Leda-Lon tube. Again this should be a good tight fit so it won’t move.

Crane swivel crimped to the backbone.

Now thread on a luminous plastic bead followed by a crimp sleeve. It is essential to have the correct size sleeves for the job. Too small and they won’t go over the mono; too big and they won’t crimp up properly.

I took the two hooks and pushed about 30mm of tube cut from electrical cable, over the eyes of the hooks as they were held back to back. This can be a bit fiddly but is designed to hold the hooks in line with the trace and prevent tangles. It also keeps the two barbs opposed to each other. The big hook is a Mustad E-Z Powerbaiter and the small one is a Tanawa long line hook. You could also use tuna circle hooks instead of thePowerbaiters.

Push the tube up towards the barbs just enough to allow the 230kg mono to be passed through the hook eyes and then back through the sleeve. Pull the end of the mono with a pair of pliers in order to take up any slack and so force the bead up tight to the sleeve before clamping down on the sleeve with your crimping tool. Then push the tube back down over the hook eyes and over the sleeve as shown in the picture. Again a little dish-washing liquid makes this job a lot easier.

Both hooks are held in place by the tube which prevents the keeper hooking fowling the gap of the Powerbaiter hook.

I would normally advise sharpening your hooks first, as you always do when fly tying, but because of the use of the tight-fitting tube it is safer to sharpen them last!

The Powerbaiter hooks have long shank with an offset barb. The metal is softer than a modern chemically sharpened hook and so will usually require a touch up with a file. Don’t get too carried away with the file or you ruin the whole rig. Take off a little from the inside of the barb only.

After repeating the process for the second dropper all that remains is to place a loop at each end of the mainline. At the top use plastic tube, Armour Spring, or a stainless thimble for maximum protection from wear at the point where your Coastlock swivel is connected.

At the bottom make a sinker loop about 150mm long joining it back to the mainline with a sleeve. It is a good idea to connect your sinker to this loop with a lighter weight mono so that if your sinker snags you won’t lose the lot. You can also use a cheap small coast-lock type swivel to connect your sinker so forming a weak-point that will break should the sinker snag.

Have fun making these high-performance groper rigs, I certainly did. The next job is to try it out on a groper!

Deepwater Groper Rig

Carrying Pre-tied Groper Rigs

For all types of fishing, it is important to pre-tie and prepare all your fishing rigs before you go fishing and store them in plastic bags ready for action. This preparation is essential when deep-sea fishing. You don’t want to waste any time when out on the water and the fish are biting. Also, keep in mind that the sea could be a bit rough and you don’t want to be looking down fiddling with your tackle. Read here about making your own high-performance deep-sea groper rigs and also more deep-sea groper rigs. Tuna circle hooks and power-baiter long-line hooks are preferred for fishing deep water because they are self-hooking.

Over rough ground, you could easily be “broken-off.” It is best to have another rig or two close at hand. After all, if you spend too much time replacing rigs on a party boat you could find that you haven’t done a lot of actual fishing when the skipper calls “lines-up!”

Keep pre-tied groper rigs in zip-lock plastic backs. Should rig be lost whilst fishing for any reason you can tie on another in seconds.