Pristine with so little development. Rugged coastline probably has something to do with that. My kinda place to visit, especially the clear ocean surrounding it. Thanks for the tip.
Same with Marco Polo trackers, good for 2mi and they really do work. Fairly cheap used but each craft would need one. Seems OP has a fun hobby looking for those lost RCs, just needs the lat/longs (like Litchi).
Why don't you put a GPS tracker on the RC Aircraft. I have been using Trakimo for years on my drones which has saved my drone several times. Just follow the app to tracker.. The new 4G version is super accurate.