This is how I determine Geo Coord in SH3.
If you'll notice the F5 screen, I've taken the "ruler" tool and connected the hacture marks at the top of the chart with those at the bottom (Meridians); and likewise, I've connected the hacture marks on the left(west) side of the chart with those on the right.
These hacture marks, the alternating white/black marks around the perimeter of the chart, are the Latitude & Longitude degrees. They only show up when you're within a certain range. If you zoom in/out too far, they will disappear from the chart.
You will also note, that I've used the ruler tool to draw in the Longitudes from my homeport, Lorient, using Roman Numerals. That way it's easy for me to keep track without having to go all the way back to the prime meridian to recount.
Too time consuming, you say? Well, think about it for a second, what was everyone doing in RL to prepare for a voyage? The grunts were restocking with ammo, victuals, fuel...
...the Navigator was futsing with charts, publication, notams, mine-field locations, wx reports.
I personally take the time to draw my course using the ruler tool from the mouth of the harbor.
I no longer need worry about the helmsman falling asleep at the wheel and drifting all over creation. 6SJ7GT's Python script with Stellarium now lets me navigate and rely on the heavens above to show me the way. I pretty much do most of my navigation on plotting sheets off screen, and so far, comparing them to the F5 screen, they are identical.
It takes 10 hours between evening twilight round of stars FIX to dawn twilight round of stars FIX, and unless you're sitting at the cpu with your eyes plasterd on the screen you'll miss the suttle drift (or in storm, major drift). I convert km into nm and use D=SxT to determine my DR and assumed position and plot my sight reductions from there...and viola, the heavens have placed where I really am, not where I thought I was using DR alone.
I've noticed, along with everyone else, that the game retards DR by about 40 nm or so...still, with Python and Stellarium, I no longer worry about it.
Cheers,
