We have been in the world of recreational diving for some time seeing how the concept called technical diving has slowly but surely installed itself in our community. Technical diving arose from having to use adapted techniques and procedures to be able to dive deeper and for longer than we could do with classic recreational diving techniques and equipment. In this aspect the so-called rebreathers have stood out. These devices have only been accessible to amateur divers in the last 20 years, but rebreathers predate the regulator that we are so used to using in recreational diving and Cousteau invented in 1944.