This quadcopter can deliver life preservers a full minute faster than a human lifeguard
From Popular Science 2013:
The Pars Aerial Rescue Robot is designed to work as a mobile lifesaver dispensary, flying out to those in need and dropping vital flotation aids until better help can be secured. As currently designed, Pars starts with a quadrotor, which makes sense: quadrotors are versatile platforms, beloved by scientists because the machines can do things like test eagle arms and Kinect-based navigation. Quadrotors are also relatively strong. That means Pars wouldn't have any trouble carrying life preservers as well as a sophisticated navigation software and infrared cameras.