Monsters of the deep

These days along the New South Wales coastline, well-equipped trailerboats are fishing the wide grounds inside and outside the continental shelf at every opportunity.

Although many of these vessels are targeting gamefish such as tuna, marlin and sharks, there's an increasing number of anglers also discovering the weird and wonderful (but nonetheless fantastic-eating) bottom-dwellers that live along the deep reefs, marine canyons and underwater seamounts.

All kinds of strange-looking and not-so-strange-looking critters, from the humble flathead to the beautiful big-eye trevalla, are getting dragged up from these deep-water grounds. It's often the case that the deeper the water, the weirder the fish; and here off Sydney, we've caught some things we haven't yet been able to identify.

On the whole, though, they're fish you do recognise - in most cases a bit bigger than normal. The Plonk Hole in 70 fathoms off Botany Bay Heads, for example, often produces leatherjackets that weigh up to 2kg or more!

This huge crater-shaped hole also produces larger-than-average nannygai, and often you can pull them up two at a time if you rig for double headers. Various species of perch, from pinkies to the deep-sea variety, are caught here, along with snapper, big blue morwong and marble flathead.

These marble flatties have a strange colouring and an unusually high, rounded back - but they sure eat well!

At certain times of the year, big silver trevally up to 2kg or so can become a real nuisance when you're trying to catch the other more delectable species.

GO WIDE
Working out wider along the inside edge of the continental shelf around 90 fathoms can also produce good fishing.

You need a good sounder to locate the hard bottom or gravel areas, and there are plenty of these patches along many parts of the shelf up and down the coast.

We've found that these areas can produce good catches of deep-sea perch, but the green-eyed sharks can be a real pain. At times they'll strip your hard-won baits as quickly as you can blink.

Fishing the many canyons or seamounts along the coast can also be fun, and off Sydney in 250 fathoms we found a unique spot called Browns Mountain. This hard, rugged ground rises up to 190 fathoms and has suddenly become popular over the past few years. When the weather conditions are settled, it's common to see a dozen or more boats drifting around and catching a range of magnificent bottom-dwellers.

BRING A PLATE
Top of the list is the blue-eye trevalla, and the very occasional hapooka cod is also taken here. Other species such as deep-sea perch and gemfish can put the finishing touches on your mixed bag.

To bottom-fish these wide grounds, conditions have to perfect; and apart from the weather, the current can also make it difficult if it's running hard. A sea anchor can be handy at times if the breeze is up, because it takes so long to get baits down and the boat needs to be almost stationary.

At times, we've even backed the boat up slowly into the breeze while the rig is dropping. Once the bait is on the bottom it usually doesn't take long to get a bite, but don't expect to feel too much action even using gelspun braid line. Most of the fish just feel like a heavy weight, and the real excitement is in pulling up the unknown.

TOUGH TACKLE The tackle most guys are using for this style of fishing ranges from large-diameter Alvey deck winches to high-capacity game reels such as 80 Penn Internationals or Shimano Tiagras.

A few boats I know have set up electric reels that can be purchased from some stores here or through the US fishing catalogues. These electric reels sure make the job a hell of a lot easier, but the boat needs to have a separate battery system with a huge capacity to run them.

Bent-butt rods can also be a real benefit for this kind of fishing, as the rod can be left in the rodholder, which makes it easier to wind the reel. It might not be fancy, but it's very practical!

Without a doubt, the best line for deep dropping is gelspun braid around 40–50kg breaking strain. Because of its fine diameter compared to monofilament, you can get plenty of it on the reel. The beauty of this line is that you can feel when the bait has hit the bottom - plus you can feel the bites, even in 500m of water!

RIGGING UP
The rigs we use are basic, and a good-quality snap swivel such as a Sampo tied to the end of the braid main line will make it easy to clip on the pre-made rigs and stop line twist.

The paternoster rig seems to work as well as any, and using two very short droppers of a stiff, heavy line around the 37kg breaking strain will help eliminate tangles on the long drops.

Over the years we've played around with different types of hooks, and at one stage we tried the Mustad and Owner brands of circle hooks. Although we caught fish on them, we missed plenty, and the short droppers were possibly stopping these hooks from working correctly.

We've gone back to the good old Mustad suicides or 540 French hooks, and because most of these fish have large mouths we find 8/0s up to 10/0s work well.

Selecting the right baits to use is very important, and something that's as tough as nails is needed so the smaller pickers won't strip the hook before a decent fish has a go at it.

The best, most tempting baits are salted strips of striped tuna and mullet, or even yellowtail fillets. The back flap or legs off a fresh cuttlefish sliced up into long strips is also a very effective, tough bait.

When fishing these kinds of depths you need everything going for you, and the idea is to pull up a fish or two - not just bare hooks!

STAY SAFE
Fishing wide offshore on any deep ground requires well-maintained equipment and a sensible approach. Firstly, the weather must be taken in to consideration - not only for safety reasons, but also because it's hard to bottom-fish these deep grounds if it's blowing more than 10–15kt.

Safety equipment comes before the fishing gear, and apart from the legally required equipment, a vessel must have an EPIRB and a marine radio when venturing even a couple of miles off the coast. These days a CDMA mobile phone is another handy safety item.

A handheld or fixed GPS is also an essential part of the equipment; not only to pinpoint a position should you ever need to, but also so you can go directly back to the recognised grounds or areas where you've found fish before. A reliable depthsounder is also essential for this kind of deep work, and it must function properly in at least 100 fathoms or so.

The latest charts available today will help you locate the many marine canyons and seamounts, but finding the unmarked hard grounds anywhere along the coast is when a depthsounder becomes an essential tool.

So before you head offshore, check the weather carefully; make sure you have the ability to stay in touch with land at all times; and let the Coast Guard know exactly where you're heading and when you'll be back.