An engine-less barge designed to remain stationary, it enables visitors to discover the mysteries of Paris's water: canals, fish, plants, insects, etc. Two aquariums of 500 and 1,500 litres are installed at the centre of the boat. An exhibition presents the natural aquatic environment of the Seine (28 species of fish, for example). An educational workshop equipped with science equipment allows children to conduct experiments. During the week, the barge is reserved for school groups. It is open to the general public on certain weekends.