All my recreational certifications were thru NAUI from my old shop in Texas. Moving to VA, I changed to PADI for Divemaster. I'm about to get my instructor certification and chose to go back to NAUI for two primary reason. First, there's more academic freedom in the way classes are conducted when teaching new students under NAUI, Second, NAUI instructors can freelance and not have to be attached to any one shop.