Let me recommend the iPhone
app "Celestial Navigation" by Dr. Harald Merkel.
I'm a beginner, too. This app has you enter your assumed position, body observed, altitude, and other pertinent raw information (no calculations whatever) and returns a line of position, even drawn on a map from your assumed position.
On the one hand, this is a cheat sheet - it makes it too easy because you do no calculations and need no understanding of what you are doing. It goes against actually learning
to navigate without electronics
, since it needs your iPhone
On the other hand, I've found it a wonderful tool for improving my observations. I can run numerous Sun sights in sequence, a few minutes apart, trying to reduce the error from my known (by GPS) location. It's wonderful practice at taking sights.
In your immediate case, it's a check against the procedure you are utilizing in OpenCPN
. If the same sight gives different lines of position, something is wrong. Obviously, you can check against GPS
, but your sight SHOULD have some error, given the lack of accuracy and precision in any sextant
sight. If you get no error, you're going to get dismissed by the people out there who are not beginners.