Ditto what Dan S said about the difference in true side-drifting which is drag-free when properly executed, versus boondogging which is literally dragging your offering straight downriver at the same speed as the surface current (considerably faster than the current on the bottom). Proper boat control is analagous to float fishing where a guy holds the float back just a little bit... just letting the float go merrily downriver will unnaturally drag your goods along the bottom.

But as so many folks have said on this board, these critters only have a pea-brain. While I consider side-drifting a higher finesse artform, dragging bait right on top of the fish is one of the most popular techniques for California steelheaders as well as Alaska king fishers. Which method is correct? Well, as they say, "When in Rome..."