The biggest challenge in rescuing someone who appears to be struggling in the water is the time that it takes to get to them. Swimmers in distress often panic and this makes the situation worse. The German lifeguard association is testing drones to see if they can be deployed quickly and efficiently to drop an inflatable flotation device to swimmers in trouble. This gives the rescuers more time to get to the swimmer and potentially save more lives.
Check out this article to learn more about how this program is being deployed.