There is a big structural difference between "very stiff" and "rigid". If there is any flex that causes motion between pieces, you need to deal with it. Flexing tends to create more flexing by working joints loose or wearing away at material.

Surfing is exactly my point with the Molokai Challenge. We don't have enough information from early explorers to know if the Aleut were surfing, but it could go along way to explain the amazing performance observed. In George Dyson's defense, he said he had included surfing as a possible explanation in the article but it was edited out. So the debate goes on partially due to the vagaries of the magazine publishing business.

> I agree that the word "definitely" is incorrect in this context,
> as we know very little of the intentions of the original kayak builders.
> The point that I was trying to make is that a very stiff kayak could
> "definitely" be built out of the raw materials available to the
> Aleuts, as demonstrated by the stiffness of the Greenland designs. In
> other words the Aleuts could have built much stiffer boats by changing
> their construction methods, but for whatever reasons did not do so.

> BTW, the high speeds obtained in the Molokai Challenge are obtained by
> surfing the large ocean swell. Of course, we don't know if the speeds
> recorded for the Aleuts and Greenlanders were similarly influenced by
> surfing conditions or as George Dyson notes in his article, from knowledge
> of local currents.

> Greg Stamer