Generally speaking cameras and water should never be mixed – Underwater cameras are an exception. The most common way of taking photographs underwater is to put the land based camera inside an underwater housing – this is a bespoke waterproof container that allows the camera to be used via connectors. Before the 1980s there were very few cameras that were purpose built for underwater photography. The French Calypso is an exception. This brilliantly designed camera was eventually taken up by Nikon and produced as the Nikonos camera. I like underwater cameras as the design is a weird mix of form following function and occasionally ‘needs must’ approaches.