A BRITISH NAVY FROGMAN SIEBE GORMAN SALVUS OXYGEN REBREATHER, 20TH CENTURY, possibly produced for the Allied Force's 'Experimental Submarine Flotilla', complete with diving mouthpiece, two oxygen cylinders (one spare), two atmosphere gauges (one spare), and webbing back straps, together with a Salvus rubber coated canvas breathing bag, a pair of World War Two Siebe goggles, the rubber frame stamped 'Siebe Gorman & Co Ltd Makers', London, with adjustable canvas and leather strap, and a copy of 'The Frogmen: The Story of the Wartime Underwater Operations', by Waldron & Gleeson, published by PAN-Books (qty)

The Experimental Submarine Flotilla, colloquially known as the 'Frogmen' were a British naval unit established in April 1942 in response to the success of attacks by a similar unit of Italian commandos, the Decima Flottiglia MAS, against British military bases in Malta, Gibraltar and Alexandria between 1941 and 1942. In the early days of the unit breathing apparatus largely consisted of repurposed Luftwaffe oxygen tanks, prior to the more widespread use of Siebe Gorman Salvus equipment in later operations. The most notable wartime operation undertaken by the 'frogmen' was the unit's attack on the Nazi battleship Tirpitz in 1942.