The base of a CTD instrument tripod, at the ASHES vent field in Axial Caldera. The tripod sits next to some juvenile tube worms growing out of cracks in the basalt, where diffuse hydrothermal fluids mix with the seawater and feed the chemosynthetic symbionts that provide energy to the worms. Credit: NSF-OOI/UW/WHOI; J2-1708; V25