Enrique, I think you will find more differences in technical agencies than in recreational agencies, in terms of how the curriculum is organized and divided, and in terms of where in the curriculum the use of helium is introduced.
BTW, you don't have to go through a lot of trial and error in technical gear, if you don't want to. I put together my gear for single tank Fundamentals, and the only things I did for doubles was buy a set of doubles regs (and I still have them) and a doubles wing (which I'm still using). Everything else I had made the transition without issues.
BTW, you don't have to go through a lot of trial and error in technical gear, if you don't want to. I put together my gear for single tank Fundamentals, and the only things I did for doubles was buy a set of doubles regs (and I still have them) and a doubles wing (which I'm still using). Everything else I had made the transition without issues.