Adding four big split shot ahead of a nymph takes the sexy out of fly casting real quick. But when you're faced with a deep, dark hole that might be home to a massive brown trout or steelhead, sometimes you have to suck it up and dredge. The drift is no different than with any nymph rig, but getting that much lead to the top of the pool without smacking yourself in the back of the noggin takes some skill.
Master the old chuck-and-duck cast, and you'll score more fish and suffer fewer welts. Just make sure you have plenty of back-cast room, because this isn't for tight quarters.
False casting is what you have to avoid, so start by feeding line straight downstream with the rod tip held high to stop the weights from snagging the bottom until you have enough length to reach the top of the hole you're trying to fish.
In one fluid motion, swing the rod over your shoulder to get the line swinging in an arc over the water behind you. Keep the line tight so it stays straight and extended. If the line collapses or loses momentum, get ready for a thump to the cranium.
When the line reaches the 1 o'clock position, hunch down, bow your head, and bring the rod straight over your body, pointing the tip exactly where you want the rig to land--or rather splash down with the grace of a rifle shot.