Steel tanks weigh less, are smaller and more durable, and require that a diver use less weight than standard aluminium tanks. Why aluminium tanks have become the industry standard then? Aluminium is more cheap material, it doesn't tend to rust like steel, so requiring less inspection efforts. Weight Aluminium is less strong then steel, so AL tanks walls are more thick to withhold the pressure of 200 bar. Aluminium tank 12L - 15 kilo (empty 13 kilo), Steel tank 12L

SS Thistlegorm was a British armed Merchant Navy ship built in 1940 by Joseph Thompson & Son in Sunderland, England. She was sunk on 6 October 1941 near Ras Mohammed in the Red Sea. The vessel’s cargo included: Bedford trucks, Universal Carrier armoured vehicles, Norton 16H and BSA motorcycles,Bren guns, cases of ammunition, and 0.303 rifles as well as radio equipment, Wellington boots, aircraft parts, railway wagons[3] and two LMS Stanier Class 8F steam locomotives. These tr