Thanks, Warren, for following up on this. The good new is that if you are correct in its use as a navigational device, then this particular instance may not be that rare after all, and there might be similar instruments in other wrecks in the Mediterranean & Black Seas. Since there are thousands of such wrecks, there may be tens/hundreds of devices to find. Perhaps some will be in better condition than the Antikythera device. Perhaps other such ancient devices have _already_ been found, but subsequently mistakenly discarded as corroded pieces of modern junk. At 09:21 AM 12/7/2012, Warren Smith wrote:

I finally talked myself into sending an email to the people behind the http://www.antikythera-mechanism.gr/ web site (who also have authored numerous articles about the device).

Here's the email I sent them.

I was stimulated by recent speculation the antikythera device was perhaps designed by Archimedes, seems to have predicted calandar, moon, sun, planets, and knew (via a "pin and slot drive" mechanism) an approximate version of Kepler's ellipse fact of non-uniform speed and non-circular motion. Then I found your web site http://www.antikythera-mechanism.gr/ and some popular press articles.

What I want to begin exploring in this email is the speculation -- which I hardly saw anyplace -- that the device could have been intended by its designer for navigational use.