Drift boats are, by far, the most maneuverable and spacious water craft the fly fisherman can use to ply the waters while river fishing. They were designed originally for the sole purpose of fly fishing, with the capability of carrying a great deal of cargo and a full complement of anglers. Perhaps their greatest attribute is their ability to allow the angler to easily stand while fishing, which is a great help in fly casting.
A major point to consider is that a drift boat is most advantageous when manned by at least two fishermen. Generally one, or more, of these fishermen will be casting continuously while the another controls the oars and pilots the boat, while tossing casts as long as he can safely and comfortably do so while maneuvering the boat. Although it is possible for the solo fisherman to use a drift boat, doing so requires the fisherman to anchor the boat and then fish from a stationary position, which defeats the greatest advantage of the vessel - its maneuverability.
The first rule in rowing the drift boat, assuming two fishermen are aboard, is to attempt to keep the boat on a parallel course with the river bank. This helps the two fishermen to place their casts along the riverbanks without fear of crossing lines with each other. A good oarsman can hold the boat stationary or even back it upstream to permit the fisherman to refloat the dry fly over an enticing eddy. Another is to never let go of the oars unless it is absolutely safe to do so. Swift rivers have a tendency to grab the blade of the oar and either break the oar or bend the oarlock, both of which are disastrous situations in a whitewater river.
Drift boats do require a different approach to oar handling in swift water than is typical of conventional row boats. The design of the drift boat with its high bow section, v-shaped hull, and blunted stern is optimized for downriver travel. The oars are used to position the stern of the boat to determine the course downstream. Pulling the oars slows the boat against the current. Steering, or obstacle avoidance, requires pulling the oars to move the stern at an angle (about 45 degrees) to the stream flow, then straightening out to proceed downstream.
A drift boat, with an adept oarsman, is perhaps the best boat an angler can have for fly fishing the swift rivers where native trout abound.