An artist's conception of how the optical modem could function using a battery powered, untethered remotely operated vehicle (UTROV). Using the optical modem, data and real-time video are transferred from the UTROV, outfitted with sensors, cameras and a manipulator arm, to surface ships. The UTROV receives instructions from a shipboard pilot, who directs it to collect samples, images, video, and other data at a hydrothermal vent site.