Rewrite for clarity and message >
My home river is a part of a limestone long chain of lakes, with joining river, with waterfalls, rapids and dams. Complex with deep lakes, shallows, river that is 100 yards wide and you can walk across, sections long enough that float planes will land, and holes deep enough that you must use metal that are beside a rock island and a shallow bay. So I fish the sections, for the time of year and how I want to fish it.
In the early season, I am likely casting with a Scandi FHI or FH2, to get the below just below the surface. There are enough ledges that going deep is not good, and there are a lot of fish that hang out in the boulders, racks and edges where the river transitions from deep to a run. Then I move down to shallow pools in the run. Flies are unweighted and as the water is fast, I believe-observe reluctance to hit top water for the energy spent.
As season progresses, and water slows, I move to Floating Head. Best action is sunrise and sunset, and I prefer sunset to get the evening flies up.
Also have good days, when the wind is high, by casting to the banks and strip, but if I know I am going this, I goto SH rod.
In the high heat of summer, I am either swinging a fly on a 2H Rod below the rapids-falls or casting into the lily-march edges along the deep pools. With the 2H, I will shift between the various heads, depending on flow, depth and what I know-believe about the water is.
In one section, the water is extremely complex .... just before the rapids, depth slow, holding pike and bass. At the mouth of the rapids, where this is a lot of structure, redhorse (10lb+, protected) sitting on the bottom, moving to the rapid, I am back to bass, and then below the waterfalls, everything, but it is deep with little shoreline. (You need a watercraft here, if fly fishing). In this section, I am fishing a SH, as some of the best opprtunities means casting upstream.
I will carry multiple heads and change, permitting it is easy and possible to do so. I have no desire to change heads, when I am 100' away from the bank.
By the end of summer, the fish are slowing down. Do have learnt to avoid the Osprey, Blue Heron, Loons and snapping turtles, by being "off-the-bite" during the day, and deep. I have a couple of times, snorkel the section, drifting and watching. Activity picks up, and as the water is slower, I am back to a floating head when swinging.
By autumn, they are down, weed is breaking, so I start thinking about a long drive for steelhead, where I will eventually transition to tip.
Then fill-in winter with fishing Bonefish with a SH.
So I am constantly moving from SH to Floating Scandi and Tips. As my experience with Spey is way less than SH, it takes sometime to re-adjust when changing to Spey or even the heads, but for me, I know this will get better with practice, practice .....
The water has so many selections available, so I select the water I wish to. Yes, I avoid deep pools.
My strategy is a little different for trout (such as brook) as most of the moving trout water are runs closer in and not deep. Pools are not very deep <6', but can be fast. Floating lines win! and mending is important. I select the fly for depth, from wet fly to muddler to conehead muddle to scuplzilla.