Sooo... now that seems to be an interesting topic 
How do you want to receive GPS locations without GSM (should mean: no phone service at all)
Over radio and type them into some kind of User Interface?
Edit: I well understood that part with starting point, angle, bearing and speed.
For sure, there exists at least some hope, that someone could code this. But as far as I know, there are several outer factors which have extreme influence on the result (wind, flow and usage errors).
The gps works fine without gsm signal, that will be the only info Locus would get.
I was there in February and had catch compass installed on my Nexus One and it worked fine I could also Poi positions without gsm signal , i also had Google earth cached, that worked to, so I don't think that would be a problem.
Wind, waves and stream is not a problem.
As i can see in Locus, the guide feature is the one to use, added som code math, time compass heading and speed, should do it, but again i'm not a dev.
ex. current position to a steady Poi, have to be my current position and to a moving Poi.If Locus got the speed and compass heading and time, then Locus should be able to keep track of the moving Poi.
If we are ready to takeoff on dek, there could be a fix button that took the position time and speed in Knots and Nm and a manual insert speed and position and time ,i got via radio.
it's just a thought.
It's very tricky to explain. :roll: