Strike Indicator Variations
Love them or loathe them, strike indicators are a great help in detecting takes when nymphing.
Placing the indicator at the join between line and leader often puts it too far away from the fly to quickly detect strikes and consequently many subtle takes are missed. I prefer to place mine partway along the leader according to the depth and speed of the water. As a rule, this is about 1.5 times the water depth above the top nymph and can be extended to two times the water depth when using heavier flies in very fast water.
On rivers like the Tongariro, the proclivity is to use giant indicators in bright colours, but elsewhere I prefer significantly smaller indicators. Wise anglers vary the size and colour of an indicator to match the depth and turbulence of the water to be fished, the brightness of the day, the angle of the sun, and the wariness of the trout.
My guide on indicator size and colour is a blend of opposite concepts. Use the biggest indicator you can get away with balanced against the smallest indicator you can see efficiently, while using the brightest indicator that doesn’t spook the trout balanced against the most subtle colour that is still clearly visible.
My favourite colours for prospecting are either burnt orange or light green polypropylene yarns. Both are clearly visible in most waters and from experience are less likely to spook trout than bright red, yellow, and chartreuse material generally sold commercially as indicator material.
If you primarily only fish to “dumb trout”, the brightness of the colour won’t make any difference! On dull days, I combine a slip of both materials to form a bi-coloured indicator. It seems that the eye is always attracted to one colour or the other where there might be difficulty picking out just a single colour.
Red or Black indicators are useful in difficult light. Whenever the sun is low in my face early morning or late afternoon, I resort to red. While it risks spooking a few trout, red shows up clearly with the light shining through it and takes are more readily identified. Black indicators in good light are almost invisible but are particularly useful on those dull days when the water surface turns to quicksilver. Because they absorb all light, they appear as a visible black hole in contrast to the grey featureless surface water. White indicators are useful under many circumstances, but become difficult to identify when fished in turbulent water or in a scum line.
I seldom find the need to fish and indicator larger than my small fingernail (often much smaller) and carry a set of folding scissors to regularly trim indicators. In slightly broken water with good light, it is amazing how visible even the smallest indicators appear. Logically, when using heavy nymphs in rough water, a large indicator might be more appropriate, but I have seldom found the need to fish super large indicators. When fishing is tough, too many anglers compromise their results by sticking with indicators that are too large.
Maybe the hardest judgement call in using strike indicators is being smart enough to recognise when NOT to use them. When it is possible to see a trout clearly, canny anglers often opt not to use an indicator to minimise the risk of spooking it, preferring instead to watch the fish’s behaviour and judge the moment of the take.