the question is whether boats designed with a slight amount of differential rocker . . . have any difference in maneuverability when heeled
I take it you are asking about heeling from a centralized solo seat.
I clarified my initial post in this thread to focus on paddling from a centralized seat because our resident solo-stern-paddling-a-tandem aficionado,
@lowangle al, had already been participating. Al has experimented with and perfected his solo style in his tandem canoes, many wood/canvas and as long as 20 feet as I recall, often from the stern—sometimes with various types of bow ballast and sometimes with none.
Obviously, Al's atypical seating position doesn't allow the stern to "crack", breakaway or slide for turns. Nor can he significantly lighten the stern for crack/breakaway by pitching forward from the stern seat. Nor can he employ the many bow strokes as effectively as a centrally seated paddler can.
It does seem to me, however, that stern seating without ballast in a long tandem will shorten the waterline by lifting the bow clear of the water. This shortening of the waterline surely helps with pivot turns on the stern, whether heeled/carved or not. I'm not sure I follow his method(s) of wind paddling.
It's difficult to paddle a wide tandem from a centralized seat and get all the hydro-physics advantages that a centralized paddler in a narrow solo canoe can. For example, it's more difficult to get a vertical paddle for forward strokes, to do cross strokes, and to heel the canoe. Therefore, Omer Stringer in the 1930s (and, in my opinion, paddlers for thousands of years before him) popularized the "Canadian style" of paddling a tandem from the center with knees offset in the chine, causing a permanent hull heel. That way, one can get a more vertical forward stroke, can lift the stern stem out of the water for relatively free-spinning turns, and can pitch the bow down to shorten the waterline. However, the permanently heeled tandem makes all cross strokes very difficult to impossible, and also converts the canoe into a big sail in the wind.
I think what I am doing predates Masons books and videos, which I think scared people away from this stern heavy style.
I don't agree that a majority, or even a large plurality, of solo paddlers in tandem canoes paddled stern heavy before Mason.
Folks who paddled solo in tandems did so from centralized positions long before Mason. Stringer was before Mason. And we have posted pre-Stringer videos on this forum of wood/canvas paddlers in centralized positions, such as Reg Blomfield and Charles River racers. It's also not difficult to find pictures of Native Americans paddling solo in birch bark canoes from the center. And, yes, it's possible to find pictures of natives paddling solo from the stern or even the bow, usually in dugout canoes.
Paddling solo from anywhere in a canoe is possible and has its adherents, but the hull and paddling physics will be somewhat different from each position, and most different from the extreme stern (or bow).
I think it might be fun for
@lowangle al to attend the October Functional Freestyle event in the NJ Pine Barrens if he's in Pennsylvania at that time of year. Modern solo canoes are available to rent or borrow from other participants. It's also fun to try paddling big tandems in different ways.
As for this thread, you folks can go in any paddling technique direction you want. It's been very interesting to me so far with the various participants, experiences and points of view.