There is a lot of satisfaction to be gained from successfully analysing the fishing situation and working out the best technique and tackle to use. On the typical New Zealand River, you can encounter any sort of water and before starting, it is worthwhile to consider what is the most efficient way to fish a particular type of water. Considering the water one might encounter on a backcountry river:
Riffles – these are usually the prime lies in any river as they provide both shelter and a food source for the trout. Fortunately for anglers, they are easy to fish as drag is not a problem and the fish take freely. So the angler can get quite close to the likely holding lies and fish with a reasonably short line. Likewise the leader can be kept to no more than 3 m to make it easy to guide the fly through the joggly water. An indicator is essential and the leader should not be less than 2.5 kg. The most successful flies are a choice between attractor nymphs or dry flies. The nymphs should be medium-weighted with a bit of a flash like a beadhead. Attractor dries need to be large and bushy like Wulffs or terrestrial patterns.
Runs – also prime lies as the depth gives trout some sense of security. Food is brought down at a more leisurely pace so the fish have more time to inspect it than in a riffle. This means drag will see a refusal and good mending skills are important. The angler needs to be more cautious as the water surface is usually quite calm and the trout’s window is very effective. Reasonably long casts are required, as long as the mending can still be carried out. Leaders should suit the depth of water but around 3 m is usually about right. Indicators are optional but should be dispensed with if the water is less than 2 m deep. Nymphs are usually the best choice unless the fish are feeding on the surface. Usually a double nymph rig will work best, with a smaller tail fly more likely to be taken than the weighted one. Close imitative nymphs like the old faithful Pheasant Tail nymph are hard to beat.
Pools – can be divided into three main sections:
Head of pool – a lie favoured by large trout, especially in the ‘eye’ of the pool. In this position, a trout can see every morsel of food coming into the pool, yet lie just off the main current. A backswirl can make for difficult fishing and ability to control drag is critical. Anglers are easily seen by the trout, as usually the casting position will be from the open shingle bank so long casts are an advantage. Similarly, a reasonably long leader is useful to avoid lining the fish. If the trout is lying just over the lip, then it is necessary to get down fast or the fly will be swept over their heads. In many places, use of a sinking line and fishing down to the fish from the safety of the rapid above is a good ploy. Soft-bodied wet flies work best in that case. Otherwise, a well-weighted sinker nymph with a small tail fly will get down to the fish quickly. Beadheads work well in the strong-flowing water, with a small mayfly nymph at the tail.
Body of pool – can hold good fish if reasonable cover available. Otherwise, medium-size trout frequent such lies. The water has lost momentum and the fish have a lot of time to inspect their food. Long casts and long leaders are essential, as the line must be kept well away from the trout. A low profile is also worth remembering, especially when casting from a bank. Often the best approach is to fish the far bank where fish are less likely to be disturbed by the fall of the line as it will be falling on the faster centre current. Flies need to closely imitate whatever is coming down the river. This is the time to have a look under the rocks or scoop insects from the surface and match the natural as best you can. Small nymphs and dries work best in the delicate water.
Tail of pool – tough fishing position. Often holds the odd good fish in the morning but they will move up to the security of deeper water when the light hits the water. The best position to cast from is down in the rapids below so that only a long, fine leader is landing on the smooth water. A small light nymph is best, as trout don’t often rise that early in the morning. Something sparse like a Willow Grub or small Caddis can work well. The other good approach is the fish a small wet fly across and down the tail of the pool, as there is less danger of ‘lining’ the fish.
Plunge pool – this is pool formed where a torrent of water pours down a small rockfall into a large pool. This is a lie favoured by large trout as they can lie to the side of the main current and feed leisurely. They may also lie in the cave that is often formed under the rockfall by the backwash water. These pools are difficult to fish as the fish can lie quite close to the waterfall. It is hard to get a fly down to them if they are lying deep. A sinking line, short one metre leader and a weighted nymph is worth trying. Otherwise a heavy nymph on a strong 3 m leader is the best bet. Where it is legal, a split shot or two clamped on one metre above the fly can prove very deadly. An indicator would be essential to keep the line floating. Big Hare’n’Coppers or large nymphs like a Bitch Creek work well.
Glides – extreme fishing! Avoid them unless you are desperate or an expert as they are too frustrating for us ordinary anglers, even though you will often see several fish lying there. The problem is the smoothness of the water and the open nature of a glide. The fish lie out in the open but are extremely wary, as they know they are exposed to predators. Any unnatural event will see them scurry for the deeper water. This may be the line falling on the water, the drag of the fly, or movement by the angler. If you must fish them, stay down and well back. Fish a long line with a long, fine leader, maybe down to 1.5 kg. Five metre leader lengths are normally the minimum. It is hard to get drag free drifts as mending can often scare the fish. Better to use an ‘S’ cast and don’t mend at all. It is best to avoid putting the fly close to the fish, as they will move some distance to seize a fly. Very small imitative dries and nymphs will work best. Often trout will rise strongly in glides during hatches. Fly sizes down to 18 might be necessary in tough situations. If you enjoy testing your trout fishing skills, this is the water to try.
The above guidelines are only general as each pool has its own specific characteristics that make it different to any other pool in the river. But it does show how you must vary your tactics to suit the water. If you think about what will best suit the water in front of you and then change your rig to suit, you will have a good day on the river.