Burnside Rescue Can
From Openwaterpedia

Bob Burnside, creator of the Burnside Rescue Can
noun - The Burnside Rescue Can is a rescue device and iconic piece of lifesaving equipment used in water rescue designed by Los Angeles County Chief Lifeguard Robert Burnside. The flotation device helps support the victim's and rescuer's weight to make a rescue easier. It is an essential part of the equipment that must be carried by lifeguards. It further can act as a mark of authority, identifying an individual as a lifeguard.
Synonym
Rescue can, rescue buoy, rescue tube