why not simply draw a circle with the boat's current position as center and the given distance (3nm) as radius and then check if the circle contains part of the coast line? the moment, the circle is empty, you're out of range.
still no scenario for an usual gps app, but the coast lines should be available with almost all data (openstreetmap frinst) and thus easily checked. _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
