: Some I've read of are a couple hundred years old.

That's pretty old. So some must be newer then? Couldn't their condition be noted by observing any collapse inside of the hulls? If one shows no deformation (hull collaps, etc.), that's a pretty good indication of a kayak holding its shape. Intact kayaks could form a good basis for comparative studies I'd think. Is it possible for a 300 year old kayak to have maintained its original form?

With regards to the Igdlorsuit kayak, it was only surveyed some four years after collection, so it wasn't likely deformed at all. Furthermore, a frame built by the same builder the same year was sent to Texas, and was never covered with skin or used-- it has held its shape perfectly, and is consistent in form with the other Igdlorsuit (Illorsuit) that folks are referring to.

: Would be ok for a wood boat
: and they usually have plans. Not great for a skin boat that as far as I've
: ever heard never had plans, so there's no way to check to see if the
: dimmensions have changed or not.

Nautical archaeologists would undoubtedly disagree with that. I've seen plenty of wooden boats less than 100 years old that have severely deformed. Plans or not, it is rare that a decaying boat will have such plans tucked away in its hull; one must know exactly what one is looking at in order to track down the plans. But your point is taken-- its a tougher task with skinboats. As in the field of nautical archaeology, comparative studies can be done as well as modelling (both in scale and full-size.) This does not "check" for changes, but does contribute considerably to the understanding of original forms. It isn't a black and white science by any means.

: Also lots of these original boats are really skinny (I've read of one that
: was I think 14" beam) fairly obviously not designed for the average
: western male of today (I'd need a really big jar of vasaline to have a
: chance of getting in that one )

Lots of them (Arctic Kayaks) are also pretty wide. There are many historic kayaks over 25" wide-- likely more than ones under 16" wide.
Harvey