In the years leading up to the Second World War, a Royal Navy diver looked remarkably similar to one from the Victorian era: clad in a brass helmet, lead-soled boots, and a heavy suit made from layers of waterproofed canvas and vulcanised rubber, breathing through a long tube connected to a compressor aboard the support vessel. The war, however, brought about the birth of the modern “frogman”, divers equipped with latex suits and self-contained oxygen supplies.