Haven't been to Belize - yet...
Covered most of the Beach Boys song - Aruba (my open water and advanced certs were done here - talk about spoiled by great vis), Jamaica, Bahamas, Key Largo - haven't made Bermuda (another 'yet').
Also done all 3 Cayman Islands, Cozumel, Riviera Maya in Mexico, Ft. Lauderdale and my big one - a week long live-a-board on the Great Barrier Reef.

Did a cool land locked one - Bonne Terre Mine in MO - you gotta go 60 feet below ground to get in the water, then it's absolutely perfectly clear fresh water. No overhead environment - no special certs needed. They have the entire place lit with very bright lights - vis like nowhere else. 7 mm wetsuit, hood and gloves required...
Don't know if they have similar in Belize, but Riviera Maya has cenote diving - essentially cavern diving, but no special certs required. Mostly fresh water, but when deep enough, you transistion into
salt water. Some overhead, but never more than 150 feet away from a place to surface. Really, really cool...
Hoping to do the Riviera Maya again this spring - I'll report back on my air comsumption... I was a very light air user before, so it'll be interesting to see if that changes. With the pressure and the underwater sights & sounds, I just find it soooo relaxing that I was so calm and relaxed I never used much air.
I earned my Master SCUBA Diver cert in 2000 at Key Largo. Yes, I do love this sport. Just really need a vat of money to do it as much as I would like...
-bogie