Filmed on location at the University of Southampton’s National Oceanography Centre, a globally renowned centre for developing technologies that investigate the world’s oceans, earth systems and biosphere, Hydromancy blends documentary with artistic intervention, considering the ocean as both a sensory environment and scientific object. As viewers, we visit a coral lab bathed in blue light, an engineering workshop, and enter a room bubbling with algae and phytoplankton. Hydromancy puts into focus the spaces and technologies involved in ocean sensing and modelling: autonomous vehicles, remote sensor and tools that measure temperate and composition. The film shifts in and out of scale and perspective, water acts as a portal to span time and space. Haunting the film is the sound of the Hydromancer, an utterance between voice, song, breath and atmosphere.