1° of latitude bigger than 60nm?

[seafarer]

Originally Posted by Munchausen

Where did you read that? Last I heard, Mather AFB taught "meridian arc" navigation until it (the Nav school) was closed down.

:hmm: Assuming by "meridian arc" you mean using a pair of dividers to measure distance (nautical miles) using the tic marks along the longitude lines of an aeronautical chart.

As to the original question, the game map is laid out in squares ... approximately 64.7 nm on a side (which is suspiciously close to 120 km). For centuries, map makers have been trying to figure an accurate way of sticking a round earth (all of it ... or at least as much of it as is displayed in the game) on to a flat piece of paper ... I'd be more than a bit surprised if the SH4 dev team finally figured out how to do it.

I have no idea how the US air force teaches navigation. But the US Department of Commerce (National Bureau of Standards) and the US Department of Defense both adopted the international standard nautical mile of 1852 metres, effective July 1, 1954. Prior to that, it was one minute of meridian arc at 48°N latitude.

The research ships and NOAA ships I used to go to sea on in the 1990's all used the international standard nautical mile. It has been the standard for maritime navigation the world over for a very long time. As a researcher, we tended to prefer to use UTM (Universal Transverse Mercator) instead, since it was more precise and easier to work with, and it meshed better with the short baseline acoustic navigation we used to have to use with our submersibles and robotic vehicles (we'd place a transponder grid on the sea floor, align it to a UTM chart, and then just work in decimal coordinates and distnaces, based on acuostic interrogations of the grid from the surface and/or the subs).

The international standard nautical mile had previously been adopted by most of world, other then the US, after 1929 (the standard came out of the Monoco International Extraordinary Hydrographic Conference of 1929).