If you have a trimix or cave cert from cmas, is that worldwide recognised? I have a friend with a normoxic trimix diver cert from CMAS and she cannot go to tdi advanced trimix course because they say that cmas is not recognised. If you go from tdi to cmas, then no problems. So a new rule of her instructor, or is it really better to take a course from tdi, iantd, nacd?