I've been to Belize twice. Stayed in Ambergris and Caye Caulker. I LOVE Caye Caulker. Much better vibe and food compared to San Pedro. Less touristy, less crowded, much more chill. A little father from the good dive sites, but not far enough to really matter. The reef off of San Pedro is spectacular, average depths from 60-90 feet with plenty of different options. You owe yourself one dive at Hol Chan. Very shallow (30-40fsw) but it is great. For deep stuff, you have the obligatory Blue Hole dive. The dive itself is cool, but not the best. It is moderately deep (just shy of 150) and you see a cool cavern, but the dives at lighthouse atoll, specifically "the aquarium" are the real treats of that trip. You really can't go wrong in Belize. Some great inland sights to see as well if you have the time. San Ignacio is like Monteverde in Costa Rica 20 years ago. A wealth of natural wonders and not too many touristas around. ATM cave is probably the coolest dry cave experience I have ever had.