Yogesh Girdhar is developing underwater robots that can explore in a more human-like way. They would have the ability to distinguish “interesting” visual stimuli and make real-time changes to home in on them, rather than robotically proceeding on pre-programmed routes, blindly collecting any and all data. He helped develop this experimental vehicle called Aqua. In experiments off Barbados, it detected something different and interesting—Girdhar himself. It followed him until he stopped and then hovered over him. (Ioannis Rekleitis/McGill University)