Hey guys, I just wanted to bump this thread because I had a new question. As I understand it, you must be PADI certified to go on the open water dives in Cozumel and Grand Cayman during excusions, and so I've been looking around for a local shop to become certified with, but the only shop I can find locally that trains people, certifies them via SSI (Scuba School International). Would this still count? I called the lady at the shop and she told me it would be fine and would absolutely count and I would be good to go. But is that true? So, SSI vs PADI.... is there a difference? If I get certified in SSI instead of PADI, will they still let me open water dive in Cozumel and Grand Cayman? No problems? Because I really want to experience the Palancar Caves!