I imagine that some sort of radio beacon receiver can be attached to these drone ships and with enough of them traveling the seas, it might actually increase the chances of finding survivors.
Or even just cover them with cameras on the outside. When something interesting happens, like a ship passing by or a human being waving their arms in the waves, it will alert somebody who can take a closer look and possibly alert the coast guard/navy.
They'll be covered with cameras on the outside, unmanned boats would be way too easy targets for piracy. You wouldn't even have to sneak aboard, just get aboard and find the expensive cargo. Set off a bomb in the engine room and then unload what you can in a reasonably safe time before someone can get close and track you. It could potentially make piracy more viable in currently safe areas.
You'd want cameras to track when anything even remotely in sight is moving unexpectedly. Anything coming close would be reported to the coast guard/navy.
There'll be heavy monitoring on these ships, even just for liability issue in case some dumb guy in a yacht sails right into them and tried to sue.
