Did I read somewhere on the forum that SSI Instructors must be affiliated with a dive shop while PADI Instructors do not necessarily have to be affiliated with a shop? Or did I just dream that?
I believe that is correct. I think SDI and TDI instructors also have to be affiliated with a shop.
That said, I have also heard that, at least for SSI, if an instructor doesn't have a local shop to affiliate with, or if no local shop will accept the affiliation, the instructor CAN be affiliated with "HQ".