I just finished reading Trout Tactics. In the book Joe Humphreys writes that, if an angler uses sinking lines for nymphing, the line will bow underwater and cause drag.
This makes sense to me. However, Charles Brooks and other anglers of his generation often nymphed with sinking lines. So my question is: How did they avoid drag?

Do any of you folks nymph with sinking lines or sinking polyleaders?