Wet fly-fishing calls for slightly different tactics. The object of fishing a wet fly is to imitate a drowned insect or the nymph stage of a fly which lives under water. In most instances a fly can be fished wet, still using a floating fly-line. The nylon leader is 3 yards (2-7 metres) long and if this is rubbed with a ball of fuller’s earth wetted with washing up liquid it will be de-greased and sink. This length will get a fly down to the bottom of most rivers, lots of small lakes and the margins of reservoirs. In a river a wet fly is cast across the current and allowed to swing down with the flow. Once the line has straightened out, immediately downstream from where you are positioned, the line can be gently drawn back. The bites from a fish during wet fly-fishing can be sudden and violent so it is advisable to use a slightly stronger leader than when dry fly-fishing. In fast water the fish grabs the fly so viciously that it often succeeds in hooking itself.
The advantage of having a floating line for this type of fishing is that you can watch the point where the leader enters the water, and if you get a gentle take whilst the fly is moving down in the current the line will pull across the surface. When fishing small lakes the fly is cast out and the leader is allowed to sink. Very often it is whilst it is sinking that a trout will grab the fly. Once the fly has sunk it can be moved gently back towards the bank by drawing on the fly line. A fish taking the fly will move the line across the surface.
The type of fly you use depends a great deal on the state of the river and the time of year. If an easily identified species of fly. On which the fish are feeding, is hatching then it is common sense to use a pattern which imitates this insect. A general way of identifying whether an artificial fly should be fished wet or dry is that the eye on the wet fly hook turns down towards the point and on a dry fly hook they turn up away from the point. Look after the flies you use and don’t keep dry flies in boxes with hook clips. Stored like this the delicate dry fly hackles will become damaged. A tip for restoring the hackles in dry flies if they do get squashed is to hold the hook with a pair of long tweezers and pass the fly across the steam from the spout of a boiling kettle. All the hackles will spring back to their original position, but take care not to burn your fingers whilst doing it.