: It's a slow day here with the snow coming down outside so I thought I'd pose
: this question. Can the BBS community come up with a standardized way to
: measure rocker? A method that is quick and easy and repeatable so that we
: can all talk about rocker and be describing the same attribute of a kayak.

I think 'rocker' is only one of several components that affect manouverability, however I also think its the major one and deserves a standard measuring technique so we can compare apples with apples.

Pygmy publishes 'upright' and 'leaned' turning radii for their kayaks on their web site, and if we want to keep it simple this may be the way to go, albeit standards should be set for how to measure turning performance (Pygmy does not state speed or sea state and doesn't say the data given is the best of many tries by Brent Reitz or an average that you can expect when you paddle the kayak, but I have no reason to mistrust them and I assume the latter. Pygmy bin bedy bedy good to me!)

If that's too simple we could probly calculate some usable numbers using block and pris coefs and/or lateral plane. But what about this (which just occured to me as I read this thread but seems to have potential): Use the ratio of the water line length to the keel profile length, (i.e. lay a tape measure along the keel from bow water line to stern waterline). You could multiply the ratio result by some constant that makes the (arbitrary) average rocker a 1.0 and makes trackers less than 1.0 and turners more than 1.0 or vice versa.

For the mathematically inclined:
(Waterline Length / Keel Profile Length) * optionalfudgefactor = Rocker Coef.

Now, I don't have a clue where my boats DWL is, but this is good because it would be better to have paddlers measure their own boat rather than use design data which may not accurately depict the boats trim as built and loaded.

Wachu tink, huh? I'll now go search for my lost ego, I know I had it the other day. I bet I put it in a safe place. Anyway I'll find it soon, it can't hide from id, so get your darts ready-