[Munchausen]

Originally Posted by Frederf

Using the big dipper is no good as I was at 3°N and 1°S latitude respectively, the big dipper was through a couple billion tons of rock and slgihtly hard to see.

Polaris is usually used when you want to determine your latitude (assuming you're in the northern hemisphere) and, consequently, you need not wait until sunrise or sunset to take a sighting. Depending on the time of year, Ursa Major will eventually rotate around to where you can use to it find Polaris. Granted, star shots were usually made at twilight so, if the Dipper isn't around when you need it, try using Cassiopeia (shaped like a quirky letter "W" with the center spike pointing toward Polaris).

Another thing I noticed is that setting the time zone to anything other than +0 Z in the settings gives confusing results. It seems to say "The local time in time zone X will be _____ when the sun is rising in time zone Z." which may be right but is entirely unhelpful. The local time that the sun rises in each time zone on any given day of the year should not be more than 10 seconds or so different.

This is really the problem. "Base Time" is not really defined. If the watch was set to GMT, it would probably confuse most players (having the sun rise at midnight would draw far too many complaints). As it stands, it's almost impossible to determine if the error is in latitude or GMT.

For example, for a D.R. of 12*15' S 115*00' E, on 26 Jun 42, I calculated sunset to be somewhere around 1745 Z. If I were to then use Fremantle as my "Base" time, correction for longitude would move sunset to 1744 "Z" ... not exactly GMT. If I did use GMT, at 4 minutes of time per 1 degree of longitude, that would be about a 7 hour 40 minute "correction."

I've also found that the calculated sunrise, the upper limb rise, the center body rise, and the red light switch happen at 4 seperate times. This notion of "The red light goes off when the sun is half way out of the water" doesn't hold true in my experience. Instead the red light tends to go off a few minutes after half-sun.

Probably because you've changed the size of your sun (or not). I left my sun at default and the switchover is consistent ... midway between one limb and the other. Or, timewise, 10 mintues ... 20 minutes to fully rise or set. The moon, on the other hand, only takes 14 minutes (thereabouts ... I haven't had a full moon yet to make certain).

Btw, compared to the above D.R. calculation, my actual present position at "sunset" was 12*35' S 114*55'E ... and the sun actually set at 1900 ... 111 minutes late.