pblanc, interesting observations about canoe chine and a more aggressive boat angle in a ferry. In general I’ve thought that a flat boat (edges not exposed) desireable for a successful ferry. As one loses the ferry angle often the tllt increases and result is a peel out to avoid flipping. I’ve thought of this as being pretty universal in both canoes and kayaks. My Taureau was extremely rockered canoe and very short. It was a difficult boat to ferry, but then again I thought everything was difficult in that boat!
Agree 100% that lightening the upstream end of the boat makes it easier to set the ferry angle. In my kayak I find myself leaning forward, unweighting the stern, when back ferrying or setting into a eddy.
One of the advantages pblanc noted of setting into the eddy stern first is that you remain pointed downstream to view upcoming drops. If I’m boating with folks better than myself and want to watch them run a drop before deciding my line or deciding if I’m going to walk then I often “set” into an eddy, That way I don’t have to peek over my shoulder with my back to the rapid to view the action.
Now back to the op, I often think of boats in terms of “holding a line” or “easy to spin”. Short highly rockered boats (creek boats)- be it a canoe or a kayak- are somewhat more difficult in this regard, prefering to spin out, or get pushed around (quick unexpected change in boat angle) and thus tougher to ferry in. Length is a factor because you want an unweighted upstream end. In general terms, rocker enhances the ability to spin a boat. You see this rather dramatically in rafts. I miss my days of filming bucket slippers with their upturned ends. Aire also made some highly rockered rafts. Not only were they easy to turn, but when they flipped they had a tendency to go up on end, making a spectacular shot. Short highly rockered boats are great for last second turns, spinning off of or around rocks, and in the case of a kayak are often designed to resurface quickly at the bottom of a drop. Not so great at holding a ferry angle in stiff current.
You used to be able to see the effect of rocker on a raft rather dramatically at the upper gauley put in. They refitted the dam for hydro but in the old days punching out of the put in eddy (holding an upstream ferry angle) was a big deal. Highly rockered boats (rafts) were more likely to get “spun out” and not make it out of the put in eddy. So faced with stiff (class 4) current I consider rocker a disadvantage “for holding a line” in upstream current. Realistically, I’m not going to be backferrying in that kind of current. Faced with that situation I’ll spin the boat around and try the stronger upstream ferry rather than attempt a downstream ferry. The raft example is extreme, but does demonstrate in a real world situation how rocker can negatively effect holding a ferry angle.
Here is a simple exercise, take three or four strokes on the same side of the boat with no correction. Allow the the boat to spin out and count the number of spins. You learn a lot about your boat that way. Someone way better than me once said “the art of paddling ww is really all about just learning to control the spin of the boat.”