Its not a bad article, but Cliff really does not delve into the mechanics of executing a back ferry and some of the pitfalls. He just says "angle the canoe about 30 degrees to the current and paddle backwards". Sounds easy-peasy.
Well, I have been involved in instructing tandem teams on how to do back ferries in whitewater and have found that it can be a bit tougher than that. Yes, executing a back ferry in mild to moderate uniform current can be pretty straightforward especially if one does not have to exit an eddy into current to start the back ferry or set into an eddy to end it. But current is generally not uniform in strength in a rapid which can require considerable expertise in maintaining the ferry angle, which can vary considerably from 30 degrees, by the way.
Yes, Cliff did skip over the issue of trim. This can be a critical consideration since many tandem teams have their boats trimmed bow-light. Trimming the boat bow light can keep it drier when going through sizable standing waves. But a boat that is more than a little bow light can make back ferries quite tough.
In strong current, the most common reason a ferry fails, whether an upstream ferry or a downstream (back) ferry is that the strong current catches the upstream end of the boat and sweeps it downstream faster than the paddler or team can act to maintain or correct the ferry angle. This can happen if too open a ferry angle is used, if the canoe must exit a calm water eddy into significant current to start the ferry, or if the boat enters a seam of much stronger current in the middle of the ferry. If the upstream end of the boat is heavier (and riding deeper) than the downstream end, this is much more likely to happen.
Another issue that can make back ferries tricky is that the ferry angle is best controlled at the downstream end of the boat. Trying to force the upstream end of the boat back against the current to correct the ferry angle once it is lost is often an exercise in futility since one is working against the strength of the current. On the other hand, pulling the downstream end of the boat in a downstream direction to correct the ferry angle works with the current. The consequence of this is that the downstream paddler in a tandem team is in the best position to maintain and, if necessary correct the ferry angle. For a forward ferry that would be the stern paddler. But for a back ferry that is the bow paddler.
Very often the bow paddler in a tandem team turns out to be the less experienced and/or less powerful paddler. And the bow paddler is at a distinct disadvantage in judging and maintaining the ferry angle looking downstream because relatively little of the canoe is visible. Looking backward makes judging the angle easier, but requires an additional element of skill to be able to apply correction to maintain the angle while looking backwards.
Here is a pretty fair video by Paul Mason and Mark Scriver on execution of a back ferry in which Paul touches on the steering and correction strokes that can be used by the downstream (bow) paddler to set and maintain the ferry angle:
I'll say one thing, I reached back ferry to a lot of people in the 9 years I was an instructor, and still to this day, and the back ferry is an art. Like plank said, it is one thing t do well on smooth class I-II river where there is little obstacles, but that is not where you will use the thing, When you need it is most likely to be when the river is tight, full of debris in right angled corners, and quite pushy and then it is note as easy-peasy as it looks.
You can't say 30 degrees is the angle cause it changes all the time to adjust your direction of travel and the speed of the river.
Lots more things to take in consideration when you are in real life situation!!
Just my 2 cents of cours!!
In the end it is a good article that would, hopefully send you looking for more instruction on the subject of tripping on wilderness rivers that have rapids...
We are leaving next friday for well who knows how long, we will be packing for 15 days I believe. The river we are going on has lots of class II rapids and a few classIII rapids and one of them being about 1km long! The river is quite narrow, and fast. We will get air temperatures around freezing, so there will be no un-calculated risks to take even if running ww river is what we do all summer long. We will have a fully decked canoe, wearing drysuits and lining when we don't feel confortable to run the rapids!
Nobody ever died on a portage.
I learned a lot about rapids by running rivers in rafts and drift boats. I always preferred a rowing rig.
In Nevada I have trouble finding experienced people to paddle with.
I found an OT Canadienne in kevlar that is 15'7" and plan to used it for a solo boat. My dog is my favorite paddling partner.