I'm reading Leonard Wright's book, Fishing the Dry Fly as a Living Insect. In it he writes (page 100 in my edition) of the across and downstream cast:
"...Then too, since the delivery is made in a generally downstream direction, the imitation will be fishing slower, instead of faster, than the current flow. ... A wet fly or nymph traveling faster than the current is doomed to failure except, perhaps, under nearly still-water conditions."
First question: Why does a fly, after being cast across and down, always drift downstream traveling slower than the current? (Supposing there fast water close to the angler and slower water farther out, where the fly is? Wouldn't the fly then drift faster than the current?)
Second question: Why is a wet fly or nymph traveling faster than the current doomed to failure, while one drifting slower than the current is not? After all, some nymphs swim or crawl. Might they move slightly faster than the current?
Thanks,
Randy