E.M.I.L.Y. is a robotic device used by lifeguards for rescuing swimmers. Created by Hydronalix, a maritime robotic company, and funded by the United States Navy, EMILY operates on battery power and is operated by remote control after being dropped into the water from shore, a boat, pier, or helicopter. Using an impeller motor to travel through water, it is able to reach victims much faster than a human lifeguard can by swimming, and it is more compact and less expensive to maintain than crewed watercraft. It can also operate in weather and surf conditions that make other rescue attempts impractical. Once it reaches the victims its foam core allows it to function as a flotation device for four to six people holding onto side ropes or handles.