It was with Aqua Safaris in Santa Cruz back when they were a NAUI shop. Since then I’ve also taken PADI advanced at Aqua Safaris (with my 12yo daughter while she did her class- figured I was driving her to all of the dives anyway) and a couple of years ago, NAUI Master with Bamboo Reef in Monterey. PADI advanced was just OW+. But the NAUI MSD was a little like that old advanced class- that might have been because I was the only student, though

. It was a lot of independently planning, then executing dives that demonstrated the required skills.