Our dolphin searching skills have reached a new level! Today we managed to locate a group of dolphins in almost zero visibility, using only sound. We headed out to sea at dawn in very dense fog, with visibility of less than 50 m. These aren’t conditions in which we would typically conduct fieldwork, but due to recent sightings we decided to go out regardless. Soon after we left the harbour, we stopped the boat and put our hydrophone in the water. Sure enough, we detected dolphin whistles almost immediately. Using both intuition and successive detections of dolphin vocalisations as a guide, we managed to get closer to the dolphins bit by bit, until we could hear their breaths at the surface and finally made visual contact just off the town of Izola, Slovenia. Despite the fog, we managed to obtain identification photographs which are key to understanding population size, trends, social structure and reproductive rates of this population. Dolphins appeared in good mood, with several youngsters approaching our research boat to inspect it and play in the bow wave. Here are some of the shots of dolphins in the mist.