...another thing to consider is your speed, that is, the distance travelled between timing your SR/SS and the time when you actually go to the chart and lay it out. It may amount to only seconds but 4s = 1' (1 nm).
Whats frustrating to me is the not having an accurate sextant for either sim. We should be able to find our position to within 1 or 2 nm. When you consider that there is over 200 million sq miles of earth surface, cel nav is really quite an accomplishment.
The "sextants" that have been generated by you mod guys only makes me salivate, but, I've been doing the same thing by holding a 30cm rule up to my screen for quite a long time now, (using ratio/proportion). I've no way of getting my measurement down to 0.1 moa as a real sextant can.
Unless one of you engineers can add altitude readings to the elevations of the observation scope with split image in order to bring down the heavenly body to horizon, I'll just have to pound sand.
Cheers,