Next, cut an 18 inch piece of 20 pound test leader material. At the end of the leader tie on a No. 2 treble hook. From there it's just a matter of adjusting the cork to the depth that you want to fish. Once I'm anchored I'll drift back far enough to be able to cast to the target rocks. When using that slip cork rig make sure the line is slipping through the cork and stopping at the right depth.
Trout can be very particular.
Fish the live shrimp too deep or to shallow and you won't catch fish. The key is to let the shrimp drift past the rocks at the right depth. The most unique thing about fishing at selected depths is that you can let the rig drift with the current. You can cover a lot of water that way. Barnes says that the size of shrimp you use is not that important.