Modern mixed-gas rebreathers are the evolution of the early oxygen rebreathers, historically known in Italy as ARO (oxygen self-respirator). The idea for these first devices dates back to 1876, thanks to the creativity of Henry Fleuss, along with closed-circuit breathing apparatus later developed by the German company Dräger, the American Charles

"Swede" Momsen, and the British Sir Robert Davis. The initial applications were as a source of breathable air for rescue

operations in mines; later, they found use in submarines in case of chlorine leaks. They were subsequently improved, thanks also to the pioneering work of Teseo Tesei, and were used in military scenarios by the early underwater Commandos, who took advantage of both the extended autonomy and the ability to remain unseen from the surface due to the lack of bubbles. At NAUTISUB DIVING, you will find MCCR and ECCR rebreathers. The

courses are conducted using the PEGASUS II PRO rebreather.