Fishing this technique is actually not that difficult but the judgement used while fishing the Waterfall Plunge needs to be honed before you cast the perfectly tied fly into an obvious underwater snag. So how do you fish a waterfall successfully?
1 - Take a good look at the structure surrounding the waterfall. If there are log jams, loose branches, or obvious snags blocking the waterfall then you might want to choose another technique to fish that hole.
2 - If no obvious snags look to be blocking your drop into the hole then cast your wet fly or nymph above the waterfall and let it flow with the current.
3 - Track the course of you fly in as natural a way as you can over the fall.
4 - As the fly plunges into the hole, lower you rod tip to track the progress of the fly and allow a more free movement as it tumbles through the white water and into the deeper water of the hole beyond the waterfall.
5 - As the fly exits the white water into the smoother waters beyond, begin to lift the rod tip and smoothly draw the fly to the surface. This simulates the natural buoyancy and activity of a fly or nymph as they tumble through the broil of a waterfall and emerge in the pool below.
It probably will also go without saying but I will mention it anyway. The use of a dry fly with this technique is somewhat pointless. I have used the standard Japanese style wet flies and American nymphs with varying success. Some work well in the immediate plunge and others work well in the tailing pool but I really like the Sawyar's Killer Bug. I not only find this bug highly visible in active water but quite in-tune with the natural entomology of a small mountain stream.As a warning I feel I must tell you that I have lost more flies with this technique than with any other yet I continue to come back to it time and time again. The reason I love this technique is simply because it is fun and it is effective. All fly fishermen know that trout love the highly oxygenated water of a waterfall pool and generally hold deep in these pools sucking up fly after fly. This technique produces fish.
I hope that these techniques have been helpful to you in your tenkara fishing and if not then I suggest that you visit TenkaraUSA.com , TenkaraBum.com , TenkaraOnTheFly.net , LearnTenkara.com or many other helpful sites or bloggers out there. I believe that the Internet is a great tool for us anglers and if it wasn't for the bloggers out there I would have never started fishing with a Tenkara rod.