Of course everybody knows that a hook is essential in caching trout. I’m pretty sure though that most fly fishers do not give much thought to the properties of a hook other than size (I’ll have something to say about size at another time). What is not well known is how trout fishing hooks for fly tying should be judged from a secure hooking perspective.
In this short post I will point out the factors that determine the effectiveness of a trout fly hook. This may well help you understand why you get those rises but struggle to hook a good percentage.
At the time of a rise by a trout to a floating fly the hook can be assumed to be lying parallel to the water surface. The trout comes along opens its mouth and turns.
As the fish turns and the angler lifts the rod tip to make a strike then the hook effectively sits up at an angle with the shank applying leverage onto the point and the point then sticks into the mouth of the trout (or comes out).
I think you will agree that if leverage is poor then the chances of hooking the trout are reduced. This often occurs when fishing at a long distance from the rod which automaticaly reduces power transmisssion to the hook itself irrespective of the trout or fly hook design.
Take a look at the sketch which shows various hook properties and in particular take notice of the red LEVERAGE distance which is the distance between the end of the eye (at which point the leader or tippet is tied) and the point of the hook … shown as red lettering in the sketch.
It is this distance (called effective shank length) that is solely responsible for the leverage. In other words the longer the distance between the end of the trout hook’s eye and the point of the fly hook the greater will be the leverage and thus the chance of hooking the fish due to leverage action. If the hook is in a bony section of the trout’s mouth then significant leverage is reqired to set the hook.
This means that short-shanked hooks will have less hooking power than longer shanked hooks and in order to save weight in a hook the shank is often shortened.
There is a second important property of a trout hook that can improve the chances of setting the hook into a rising trout. This relates to the “Gap or Gape.” The wider the gape the higer the chance that a fly hook will set into flesh quite simply because the hook takes up more space inside the trout’s mouth. On the other hand the wider the gape the more of an angle between the leader and hook point at the time of the strike occurs which would tend to lift the point away from a surface touched by the point.
An ideal situation would be if the pull from the line or rod lift/strike was exactly parallel to the shank. In other words no angle between line and point. This is impractical but what is important is to minimise the angle and this is achieved by optimising the ratio of effective shank length to gape width. If this ratio is high the hook will have a great penetrating power for any size hook.
Next time you have one of those days when the fish are getting off try a fly with a higher ratio of effective shank length to gape … hook that fish by understanding trout fishing hooks better.
Trout fishing hooks with “Sproat” bends take advantage of higher ratios as explained above.
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