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The number of comments indicates the number of mariners who would bother trying this method.
We were taught something similar, but for very high angle sights ie the ship’s latitude is close to the sun’s declination and you can get three accurate position lines over a short time to produce a fix without calculation by plotting the sun’s actual position on the plotting sheet for the three sights. The three elevations can be quickly converted to miles, set on a pair of compasses and plotted.
I did it for real only once in life at sea, and was very proud of my result, so probably about as useful as this suggestion.
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I was taught back in the day how to do this, but with the caveat that getting the exact time of passage correct was not easy from a moving sailboat and thus it was not especially accurate.
We were supposed to start before meridian passage and take a series of sights at even intervals and plot them, throw out the obvious outliers, and pick the spot on the curve that looked like the exact time of passage.
I can’t recall actually doing it much though.
Question: If ancient memory serves, one had a longitude fix more or less as accurate as your watch and sight, plus one could plot it as a conventional sun sight that would be latitude and thus there you had a fix. Was that possible?
I don’t think it’s that people would regularly use this, but that it’s one of the types of calculations required on deck officer exams. Your CelNav was from RAN right? I don’t know how in-depth they get into all the different types of calculations, but the running fix you mentioned is of course a staple.
The technique described is a clever shortcut, it’s based on the same basic principles as a running fix. There’s three LOPs and because the times used before and after LAN are the same so no plotting is required.
The videos are very good, high quality.
I always got our apprentices to do one of these sights. We were generally on a voyage through both hemispheres so we had the opportunity .