Are long casts overrated when fishing for steelhead on the swing?
Generally, we think so. Imagine a long wide run with approximately constant depth and constant water velocity all the way across and where the steelhead are equally likely to be holding anywhere in this run. When fishing down this run on the swing, should you make long casts (e.g. 80 feet) or short casts (e.g. 60 ft)?
In our experience, many excellent steelhead fishermen and guides would tell you that the long cast is better because you’ll cover more water. In contrast, our analysis here shows that the short cast may be better for most anglers. Not only is it easier and less physically demanding, but also you can effectively cover more water in a given amount of time.
For example, with a cast at 45 degrees that swings to hangdown (0 degrees), the water covered by the fly is roughly 1/8 of the circumference of a circle with radius equal to the length of the cast. For a 60 ft cast, this works out to 47 ft of water covered. For an 80 ft cast, it’s 63 ft of water covered. So, obviously, the 80 ft cast covers more water.
But now, let’s look at water covered per minute. Suppose that on the swing, the fly moves at 1.5 ft/sec*. Then the swing time is 47/1.5 = 31 sec for the 60 ft cast and 63/1.5 = 42 sec for the 80 ft cast. Add, say, 20 sec to both for the time it takes to step down and actually make the cast. Then add, for the 80 ft cast only, an extra, say, 10 sec for the time it takes to strip in 20 ft of running line prior to casting. Then total time is 31+20 = 51 sec for the 60 ft cast and 42+20+10=72 sec for the 80 ft cast; and the water covered per minute is 47/(51/60) = 55 ft/min for the 60 ft cast and 63/(72/60)=52 ft/min for the 80 ft cast.