RE:fly presentation techniques
Before moving into discussions about holding water, there are a lot more presentation notes to cover. I've only got my little slice of thinking on this topic but it's an area that has raised centuries worth of contemplation on the rivers of the world. Although the trout doctors of the world may have a myriad of such presentation nuances to cover, the steelheader (as I know him) is a pragmatist, a hunter, an optimist who swims his pet flies in the mysteries of the river's promising features. The connection is not so much one of following the observable actions of the fish like it is in trout fishing - it's more like the making of a connection to the psyche of the steel-forged searun rainbow; to appeal to some deeply imprinted notion that lacks inhibition in the giant trout's mind, to invoke a split-second of weakness from it's steadfast goals to defeat the river's obstacles - to achieve that which many consider to be among the most worthy of challenges in flyfishing - the steelhead on a fly.
And I don't mean with split shots, or slinkies and strike indicators... I mean with a greased line and a Spey fly in the surface film, or a riffle hitched deerhair caddis waked high and dry. Moved, hooked and landed like it was meant to be done.
And so the third primary technique... the greased line / broadside swing. In this technique, the fly is cast slightly down and across, where the rod postion and mending maintain the fly in a nearly crosswise postion to the current (and thus the fish). The fly is "led" down and across toward the near bank, maintaining an effect where the fly distinctly swims across as it drifts downcurrent in the lie. By leading the fly through the whole lie, the rod ends up pointed downriver toward the shoreline trees by the time the swing has advanced to it's end. Because of the position of the fly, when a fish strikes the hook is almost always in the near corner of the mouth, ensuring a high probability that the hook will not be thrown. This technique, or at least the way I employ the technique, is particularly good for provoking aggresive fish during twilight hours.
I like to cover long bouldery somewhat non-descript runs with each of the three techniques before stepping to the next position. Setting the deep swing works best when standing in rapids positioning the fly into a deep trough just downriver. The standard swing works well when covering large stretches of holding water, searching out aggresive fish. The broadside swing has produced best for me at first light and dusk then fish move into the trenches and pockets near shore, and are prone to be triggered into aggresive strikes as the fly scurries across their strike zone.
Regardless of which cast and presentation technique, the fly swings into a downriver position before each subsequent cast. What you do during this finishing moment is important - a very large percentage of the fish you hook will occur on the "hang down". There is plenty of fishing left at the end of the swing, especially where the currents are complex and there are opportunities to mend to either side to keep the fly swimming provokingly.
Next - the hang-down technique...