The discussion here reminds me of something I have read in Kahnemann's book: we take a 100% correct DIFFICULT question and "reply" by giving a 100% correct answer to ... a similar, EASIER, question.
Effective, but not truly moving the world forward.
So let me reiterate and reformulate the original query. (Hoping not to induce any thread drift in the process.)
Is it possible, using (one) OpenCPN, to plot two gps signals at once?
If not, can such a function get implemented in future versions?
For the purists, on 'why': Imagine you are in your boat
(gps 1, or 'own ship') while your partner is in the dinghy
, carrying a gps tracker in their pocket (gps 2, or 'a mobile gps'). Now you want to see where your partner is on your OpnenCPN plotter, in reference to your own position. The same applies to a towed object with a tracker. Etc.
PLS do not reply with 'use a portable ais device' as this is another story and portable ais devices are far more expensive and more difficult to build at home. A gps tracker can be built of a simple puck
usb gps plugged into a travel router. Or you can use your smartphone as a tracker.
A good work
around (by substituting nmea headers???) could be a fine solution too, except I think we do not get and ais sentence by simply swapping the header on say rmc. (Or do we?)
Big kiss for keeping the whole thing alive and kicking.