I guess some of us forget how spoiled we are, having the convenience of scuba instruction very nearby. I am in the Dallas, Texas area (Sunnyvale, 16 miles due east of Downtown Dallas), and there are dozens of Dive Shops offering scuba instruction, many with their own pools, in the Dallas area. Less than 5 miles from my house, there is a local dive shop in Garland, Texas with a heated indoor 12’ deep saltwater pool on site that offers certification courses. If that is an option, by all means do it. But if you are not one of the lucky ones with scuba instruction conveniently nearby, doing the book work online and finishing up with both pool work and certification dives in Cozumel might be your best option.
Even in Dallas, doing the certification dives can be an adventure. If the weather is warm enough, the instructor might take the class to Possum Kingdom Lake, west of Fort Worth, where the visability is about 6-10 feet on GOOD days. I did my Advanced Open Water dives there (years ago 1994, I believe), and it sure was really spooky at 100’, with zero visability without lights (all light from the surface was completely gone by the time you got to 30 surrounded by dead trees, it was like a scene from a bad horror movie. My Open Water certification dives (in 1989) were at Balmorhea State Park in west Texas, a small spring-fed lake with a year-round water temp. of about 75 degrees, decent visability, and maximum depth of about 35’, a good place for certification dives, except for the 11-hour drive from Dallas (for those of you unfamiliar with Texas, it’s a DAMN BIG STATE!). Still, better than the murky quarries some folks use for local diving.