I've been playing around with equal-rockered solo canoes in moving water long enough to have gotten at least somewhat familiar with how touchy the tracking can be when moving backward unless one performs a quick weight shift toward the bow to make the bow (which is now the trailing end) more "sticky". I find that in tight quarters in moving water, the ability to do a nice controlled backferry is a key skill (I'm still working on it - it was a lot easier with a double-blade, but now I've dedicated myself to a single-bladed paddle, and "mastery" of going backward is a long way off!), and it can be handy to power the boat in reverse for other reasons too.
I have yet to paddle a canoe with differential rocker, but it makes sense that "backing up" with good control in such a boat would be tougher, since having more rocker on the end of the boat that naturally becomes more prone to side-slipping when backing up would make that complication even more pronounced. I have no concerns with how a differentially rockered boat will work on flatwater where forward travel is the rule, and I think someday I'll get a solo tripper with differential rocker for just that purpose. However, for moving water that for whatever reason requires precise maneuvers, including backup skills, it seems to me that differential rocker could be quite a handicap.
Just as some background to this question, I have no fear that semi-whitewater boats with equal rocker will be around for the foreseeable future, but general-purpose solos with that trait seem to be getting scarce, and I'm still mourning the demise of Mohawk and their venerable Odyssey 14, a boat I consider myself lucky to have acquried just last year. Anyway, I got to thinking, if I wrap the Odyssey around a rock someday, what will I replace it with?
I mostly hope to hear from people who have actually experienced the difference when applying reverse power on boats with both styles of rocker. I'll be doing "test drives" of my own pretty soon at a friendly boat dealer near me, but until then....
What Eric said
All of the whitewater boats I’ve paddled are asymetrical with more rocker up front. I don’t notice any trouble back ferrying or even running rapids backwards.
It may be more of a problem in river tripping or flatwater boats with much less overall rocker.
The Osprey I paddle is a quirky boat but again I’ve not noticed any real problem backpaddling. My Explorer , the only symetrical boat I own, does not seem any better at running backwards than my other boats.
Best I can figure the things that make a boat perform better or worse are pretty subtle. Rocker specs are notoriously inconsitant from manufacturer to manufacturer. I’d be inclined to paddle a boat some before I decided how the rocker, differential or equal affected it.
backwards with differential rocker
I like boats around 15 feet plus for general use…not sure if you use shorter boats in faster water than me.
I find that each boat is quite different; some boats with differential rocker might be a bit more squirrelly that a symmetric boat going backwards but really many work just fine. I could go backwards all day long in a Merlin II on a calm lake…the boat actually still feels faster going backwards than a symmetric boat like a Wildfire, but the boat is still longer with less rocker than a Wildfire so maybe that makes sense. Symmetric boats typically have more rocker than assymmetric boats so hard just to isolate the differential rocker variable when absolute rocker and aspect ratio are in there too. If you’re in a eddy surrounded by fast water then I think you want a nice short symmetric boat with lots of rocker for maximum “obedience” to your paddle.
15’ Mad River Synergy is very well
behaved when paddled backward. My decked c-boats have also been willing to be paddle backward, although with my slalom boat so willing to spin, back ferries are seldom worth it.
Maybe it’s because I am so tall, but I have never found the blade face flipping back stroke worth it. I take the entire backstroke with the convex side of my curved blade.
Differential rocker
My experience in moving water (no serious WW – just thru Class II) is that differential rocker slightly aids such maneuvers as backferries, since the stern tends to grab moving current. I suppose the other side of that equation would be that the less rockered stern would hinder “backing up” if one wasn’t careful to remain parallel with the current. I can’t really say I’ve ever found that to be a problem though, it’s a matter of getting used to how a particular boat behaves & then being in control.
Other random thoughts regarding differential rocker:
I regularly paddle two different canoes with differential rocker: a Bell Wildfire RX (now Yellowstone Solo) and a Swift Shearwater (Kevlar). Both boats track relatively hard (compared to some equal rockered canoes) yet are reasonably maneuverable - if heeled a bit. The sticky stern of these boats does hinder spins if turned while “flat” (not heeled), which is a bit of a drag in my opinion. When I paddle in the cold winter water of Southern Ohio streams I tend to not heel very much (just a bit) for obvious reasons.
From what I understand differential rocker is primarily used as an aid for straight tracking. Since I don’t have any problems making a symmetric boat track straight and I prefer more maneuverable canoes I have come to prefer canoes with equal rocker fore and aft.
Since I have one of each I often compare the performance of my Merrimack Baboosic to my Bell Wildfire RX. Certainly there are many hull differences and one is composite and the other ABS. In the end both are 14 foot canoes. I greatly prefer the Baboosic’s handling characteristics. The WF has differential rocker – the Baboosic has equal rocker. I think this has a lot to do with my preference for the Baboosic. The Baboosic is far more maneuverable – just flat out more fun. It should be noted I suppose that though I primarily paddle moving water I’m into Freestyle. So I like to do some “dancing” as I paddle along. Give me an equal rockered canoe anytime. Any advantages of differential rocker are lost on someone like me – at least for how I paddle.
My conclusion about differential rocker is that it’s like training wheels on a bicycle – after a while you don’t need them – and they’re just in the way. …just my two cents worth… opinions vary I’m sure.
Regarding ferrys, backferrys
Once a ferry of any kind is underway and you have passed the eddyline if there is one, it’s nothing more than straight-ahead paddling as far as hydrodynamics go (if you look at how the hull moves through the water itself, and NOT at your path the boat takes through space relative to a fixed point). That’s why I was afraid the bow would become squirrely when backing up - for any reason - not just when ferrying in reverse. Your comments agree with many others I’ve heard regarding the utility of differential rocker for people who want maximum versatility. There’ve been some comments here regarding taking pretty serious whitewater with boats that have differential rocker but also are already highly rockered, but what you say about the Wildfire vs the Baboosic is the sort of info I was hoping somebody had experienced and would provide. I’m sure there’s often a lot to consider regarding other aspects of asymetrical hull shape too, as the first poster says. This is something I’m going to try to pay more attention to whenever I get the chance to try other people’s boats. It looks like the answers may not always be obvious.