I am finishing up a NAUI closed water diving June 2nd. I am thinking about doing my open water certification in Cozumel. I told my NAUI instructor this and he doesnt recommend it. I will be going in September, so a wait of 3 months before completing my open water dives in Cozumel. Is there any drawbacks to doing this on vacation? It is cheaper 220 versus my NAUI instructor wanting an additional 325.00 after i already paid 200.00 for the closed water diving. I know i could have gotten my training cheaper if I drove out of town, but this was offered in my town. any thoughts?