I always wondered how they controlled these things. Radio doesn’t travel well through water.
That’s why it’s autonomous.
It just does what it feels like.
ELF?
ULF. Or simply stick an antenna up for instructions. Small subs like this would be very very hard to track.
As far as I know, before launch operators have to set waypoints that the sub can travel to without communications. Then it can either surface to get more instructions or simply go ahead and execute some set of previously loaded instructions, whatever they may be.
Low frequencies do.