The autonomous version will go on sale next spring for $3,500, says Tony Mulligan, CEO of Hydronalix, the Arizona company developing the 'bot, and will work alongside human lifeguards. "Most lifeguards have spent their life in the ocean, learning how it acts. You can't give that experience to a computer," says Brandon Chapman, a Zuma beach lifeguard who tested EMILY. "But I don't have sonar. If I was out at sea, I would be pretty stoked if EMILY showed up."