: Perhaps a hard time calculating in advance but certainly not difficult to
: observe.

We are talking here about measuring weight, And your comment is true. While I know of no recorded history showing calculations for displacement that predate Archimedes, there were already boats in existence in his time. So, obviously the boatbuilders had worked out the kinks in building these things without the benefit of advanced math.

:While computing a numeric figure for volume is not done by the
: native builders, building mistakes from too much or too little volume, bad
: cockpit placement, etc, are painfully obvious to observe in the finished
: kayak trim and would be corrected in future efforts. Years of trial and
: error and careful observation can accomplish much, even create a match for
: kayaks built by our technologically smug culture. There is much condensed
: wisdom contained in the anthro measurements.

OK, I can buy your argument 100%, right up to the last sentence, which seems to stray a bit from what you are saying previously. Observation, and trial and error over a period of time will certainly lead to improvement.

The dispute, I feel, seems to come not from the use of anthro measurements to convey information from one generation to another in a primitive society, but from my belief that these are misused by a modern society to forecast performance. It seems to me to be a case of putting the cart before the horse, so to speak.

In a society that doesn't use tape measures it is perfectly reasonable to measure horses by handwidths, distances by paces, and so forth. If a boat rib must be 3/4 inch in diameter, it is closer to being the thickness of my thumb than my little finger -- and I can describe it as such. But it is wrong to think that a person with a smaller thumb (or a larger one) must have a boat with ribs that are proportionately smaller (or larger).

In the first case we have a description of what really and truly works (or worked) expressed in a manner that can be comprehended by anyone in that society. In the second case, though, we are trying to use the descriptions of what worked, and adapt them to (usually) larger people. We are changing parts of the data, but not necessarily in the proper proportions. Since college I have almost doubled my weight, but my height, shoe size, arm length, and the size of my digits has stayed within 10% of my college measurements. A boat built using these pieces of information would not fit me. In general, "scaling" like this sometimes works, but mostly it is a bad idea.

I just saw a show on the History channel that mentions something similar. The Wright brothers, and many others, made flying models years before an airplane was built that was capable of holding people. The conclusion of the show was that many of the designs failed in the larger sizes because the designers tried to scale them up linearly, and that just didn't work.

Imagine if you will a canoe scaled up to the length of an aircraft carrier. A single huge thwart amidships would not offer enough support to the sides of such a craft. Or, go the otherway, and imagine a hull designed for an aircraft carrier scaled down to 16 feet. It would be far too thin and tippy to paddle.

I have no problem with describing kayak or canoe specs in feet, inches, picas, meters, cubits, fathoms, hands, or chains. But, there is no magic in these measurement systems which allows them to do more than that. They describe, not predict. If I want a boat built to a primitive craftsman's specifications I'll find out how big his thumb, hand, arm, etc. were (and probably get those figures in the metric system) and build a boat to suit him. No bigger and no smaller.

If I need a bigger boat (and I do!) I'm going to be forced to look at some different designs with different proportions. Now, I have no doubt that a primitive boatbuilder who had some seasons of expertise could probably size me up by eye and build me a boat. But mine would be 8 arm lengths long, and 1 arm length wide, while someone else's boat would be only 6 arm lengths long. Again, he would be describing what worked, not measuring my arm to predict how long of a boat I needed.

Hope this isn't construed as a flame war. I certainly don't want it to be one. I have a tremendous respect for the work accomplished by people who built boats long before the word "technology" was created. But we now have the ability to measure more accurately, and model ideas on computers. Unless I want to build a museum piece (and sometimes I do) I'll use whatever modern tools I have at hand.

Just my opinion here, of course.

PGJ