If a standard transmitter/receiver is used, expect some pranksters to interfere and use the boats as giant R/C models in a very short time (or someone stealing them).
I fail to see how someone hanging over the bow, probably to rescue someone/-thing, would be able to control a regular transmitter, as it usually takes two hands.
Perhaps a little lateral thinking should be applied, to conjure up a handsfree control (like jaw movement or similar).
Do rescuers wear helmets?
Freshwater or sea water?
To get just a tad on topic, build a robot to run it