When I was first introduced to fly fishing for pinks in a river the instructor had us put a lead core line of about 10' onto the regular floater. Leader attached to the shooting head (lead). Got down for the pinks and also worked on the summer runs and springers that were in the neighborhood. But, we were fishing in 3-5' of water so I don't know just how much more would be needed to go deeper. Cast pretty well one-handed; I was using an 8 wt Fenwick.