Pinpointing the location of a hydrothermal vent can be like finding a needle in a haystack. Explorers utilize several technologies and clues to help them hone in on the location of active vents. Multibeam and split-beam sonar systems and CTD’s (Conductivity, Temperature, and Depth profilers) are tools that researchers use to narrow down the location of an active vent field. Backscatter data from the suite of sonars can show where gas bubbles and hot water are billowing out of a vent into the water column. CTD’s can also detect anomalies in the thermal and chemical signatures of the water column that are associated with vent plumes. Once researchers are confident they have found a vent field, they can plan a dive for the remotely operated vehicle (ROV) to explore the vent in more detail. As the ROV gets closer to the vent, pilots keep their eyes peeled for signs of vents like chimneys, bacterial mats, and vent animals to know they’re in the right place.