A Good Rolling Kayak

[Rob Hazard]

Has anyone done research into what design elements or specific features help make a given sea kayak an easy boat to roll?

I DO know that some kayaks are easier to roll than others, and I also know what looks generally "good" to me in a kayak design, but I haven't had the chance to experiment with rolling lots of different boats, so I don't know how my "eyeball logic" relates to reality.

Any ideas?

[KenC]

I'm a newbie kayaker, so although I have some ideas, I won't presume that any of them are any good. You might get a LOT of input by posting your question at the ...Greenland Kayaking Forum (http://www.qajaqusa.org/cgi-bin/GreenlandTechniqueForum_config.pl) at QayaqUSA

[ 04-28-2004, 08:44 PM: Message edited by: KenC ]

[Todd Bradshaw]

Assuming that we stay within reasonable beam and cockpit depth parameters, I think it's much more a matter of how the boat fits you than what shape it has. Anyone who has a decent roll should be able to roll most kayaks without problems as long as they aren't flopping around inside the cockpit in the process. Granted, some rounder-bottomed and/or rounded-deck models seem to take less energy to spin and may do it faster, but they also may be more difficult to stop when you reach the top again. Hopping into a truly unstable kayak, like a downriver racing boat, rolling it over and giving it a firm stroke and lots of hip snap can sometimes produce the dreaded "roll-and-a-half" where you see "upright" pass before your eyes on your way past it and back down. You quickly learn to take it easy and use a bit less force when rolling it. I suppose my favorites are boats with fairly oval cross-sections and fairly low decks, like slalom boats and a few sea kayaks. They are pretty stable both upright and upside-down, tend to want to settle into one of those two positions, and resist anything between them. Once you get them up to a certain point, they're going to come all the way back up and stop there all by themselves.

In any case, proper bracing is 90% of the answer. If you can roll and the boat fits you properly, you can roll it. If you're not able to keep yourself snugly in position and to use your knees, legs, feet, etc. to aid you, it doesn't matter what the hull shape is, you won't have a solid roll in that boat.

[Don Maurer]

The easiest kayak I have ever seen to roll is a Dagger Crossfire, although this is a whitewater kayak. I believe the attribute that make it roll so easily is the fact that it is essentially banana shaped with a fair amount of volume at the two ends. It is very ustable upside down, and will immediately roll onto its side. From there, it takes very little bracing or hip snap to roll it upright. As Todd said, there is no substitute for learning a good rolling technique, and once you have developed a good roll, you can roll just about any kayak, so long as your feet, thighs and butt all remain tightly in the boat.

[JimD]

And if you're building your own you have the perfect opportunity to make sure the cockpit has a customized fit.

[Todd Bradshaw]

Limiting excess space between the seat sides and your hips helps a lot, but having some sort of deck convolutions or internal bracing or foam blocking to keep your knees from sliding around, side-to-side under the deck is even more important. Once you have managed to block things enough that you can really solidly lock your lower body into the boat when you need to, you have a tremendous amount of leverage available and your knees are essentially controlling the boat. Eventually, when you work up to hands-only rolling, without a paddle, it's about 75% knees and in some ways, you're almost "kicking" the boat back upright.

On boats with smooth deck shapes a couple of carved-out mini-cell foam blocks glued under the deck to hold your knees in position can drastically increase boat control - and not just for rolling.

[Rob Hazard]

I hear what you all are saying about customizing the cockpit for good fit. Agreed.
And granted that my rolling skills could use improvement. No argument! :D

At the moment I'm thinking more about what you look for when choosing a design or eye-balling a boat you see on somebody's roof rack.

For example, I feel a boat with a low, flat afterdeck is easier to roll than one with a high deck aft. Easier to lay back in it.

And, as Todd mentioned, there are boats that sort of "snap" upright, and others that will go right on over again!
I'm curious about how you can evaluate them without building , or borrowing, and trying, every single one.

[JimD]

I'm curious about how you can evaluate them without building , or borrowing, and trying, every single one. Logs roll very well, so a roundish hulled yak with few appendages such as skegs or rudders or those high, upraised stems and sterns ought to roll the best but as already mentioned will keep on rolling after you want them to stop. But Rob ol' buddy, no disrespect intended, but I'm curious as to why you are so curious. Perhaps there's a scientific study on the perfect rolling design but who would ever build one or want one?

[Todd Bradshaw]

Other than a very vague generality, I doubt eyeballing is going to be very accurate. Even if you had the lines and section drawings for different hulls I doubt you could make much more than a moderately educated guess. Kayak designers don't spend a lot of time figuring things like fore-and-aft trim or stability for upside-down hulls. Even if they did, it would be the first thing sacrificed in order to generate designs with good windage balance, cargo capacity, surfing and paddling characteristics while right-side-up. Without taking the lines drawing, measuring the section volumes and calculating the resulting up-side-down trim it's hard to even predict exactly how much and which parts of the boat are going to be underwater and affecting the boat's resistance to spinning.

Since most types of rolls work on the principle of bringing the boat up before bringing your body up, there is something to be said for cockpits with low sides and low back decks. Some low-volume whitewater boats could even be categorized as rolling "play-boats" compared to bigger touring boats that roll fine, but don't seem to have the same snapy rolling characteristics. Much of this is due to the low decks and cockpit sides on the whitewater versions. They allow you to stay down or lean out longer, delaying the point where the rim hits your body and you have to come up. On the other hand, for touring kayaks, cockpit depth generally has to be factored into the rest of the design and the boat's intended volume, use, etc. so it may not be practical to stick a play-boat cockpit in a 400 litre expedition hull.

In any case, once you have a truly solid roll and you've outfitted the boat with a properly-fitting cockpit, you should be able to roll just about any kayak without worrying about whether it rolls easily or not. In terms of selecting a boat, how easily it rolls compared to similar models should be way down the list of selection criteria compared to right-side-up characteristics and even such things as the comfort level of the seat. -- In the words of Derek Hutchinson, one of the fathers of modern sea kayaking - "Rolling is a sign of success...having to roll is a sign of failure..."

[ 04-30-2004, 01:52 AM: Message edited by: Todd Bradshaw ]

[LeeG]

an "easy boat to roll",,,,compared too...?
what is the goal in the determination,,how to look at two kayaks and say one is easier to roll than the other or look at one boat and say "that's an easy boat to roll" without a reference?
Once you get to skinny and outfitted you're pretty much in the ball park. I'd suggest checking out the greenland site mentioned.

[Rob Hazard]

Thanks, Ken, for the Greenland Kayaking site. It has lots of the kind of stuff I was looking for.
And thanks, too, to everyone else who responded.

I started this topic out of idle, but genuine, curiosity.
Ten years ago I built a Greenland style stitch-and-glue plywood boat to plans that WB mag sold for several years, but has since stopped carrying, called "Seguin".
It's a slender and tiddly boat, ~18" wide at the chines, and not a relaxing boat for long passages. It rolls well enough, but not like a white-water boat, of course.
I'm still happy enough with it that I'm not about to build a new boat, but you know how it is; you're always looking.
So I started wondering if there's a trade-off point between stability and roll-ability, the way there is between tracking and turning, or specific design elements that enhance or hinder rolling.
Obviously I've got to try some different boats this summer!
I'm going to snoop about in the Greenland forum now.

[LeeG]

what kayaks have you paddled and hows the hip/thigh bracing in your sequin?

[Rob Hazard]

Lee,
I re-padded the cockpit of my Seguin a couple years ago and improved it vastly, and a fellow who teaches rolling locally looked at the fit and pronounced it OK. That said, I suspect there's still room for improvement. I'm thinking about moving the knee braces aft a bit.
As to other boats, it's a while ago now and I'm having trouble with names. (CRS disease!) One that I do remember particularly was a Caribou, a lovely boat built by a guy in Maine who has since sold the design to Current Designs.

[John E Hardiman]

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