I've been to Coz. Just returned from Ambergris last night. I was uninterested in going back to Coz again. But I would go back to Ambergris in a heart beat, and do indeed plan to.
Coz of course has excellent diving, if you go for drift diving. Viz is great. Fish life is fine. Beaches are horrible. And life on land is not very interesting, at least to me. It's a place for diving, with comfortable resorts where you can off-gas and ready yourself for your next dive. But watch out for the cruise ships dumping throngs of happy shoppers into the center of town.
Ambergris is more understated and laid back and the main town, San Pedro, retains a strong local cultural flavor. And the cool propeller plane puddle jump from Belize City to SP sets the tone--I sat in the copilot's seat, with a total of 8 passengers (and the plane was full). "No shoes, no shirts, no problem," that's their motto and it obtains everywhere. Right now is high season, and my wife and I kept asking each other, Where are the throngs? Nowhere to be found, thankfully. There are loads of restaurants, from very local to more upscale, and the food is always fresh and sensational. The ubiquitous hot pepper sauce is habernaro and wonderfully deadly (we love spicy food). The people are over-the-top friendly, infectiously so. The island is safe. I left wetsuits and shoes and other stuff on our villa porch, and sometimes didn't even lock the door when going out. No problem. As for diving, I dove only the local reef and it was better than excellent. Nurse sharks (big ones) and spotted eagle rays and turtles and giant grouper and parrot fish and morays and the usual fare of colorful reef fish--all in abundance. What I was struck most by was finning over dramatic cavernous canyons, one after another on all dives. All my dives were off a smallish boat with 4 to 8 people. I had the good fortune of diving for four days straight with three sensational divers from Delray Beach, two of whom are well seasoned instructors. On our last morning of diving, we were joined by ScubaERdoc (I that's his name), from this board, and his wife.
Want to charter a small boat for snorkeling or fishing? No problem, and not prohibitively expensive either. My wife and were walking barefoot down the beach by a stretch of restaurants in the dark with a bag of grouper and grunt fillets from our afternoon fishing and a guy sitting on some steps said, Hey man, I'll cook that fish for you. In twenty minutes we were sitting at a table on the beach eating perfectly blackened fillets garnished very heavily with red and green peppers, cucumbers, carrots, onions, etc, along with a mound of cocunut rice--US$7.50 each. And this was after we polished off a conch ceviche. We cracked our own bottle of wine. I don't recall this kind of laid back and informal island scene in Cozumel. I don't even think there is much of any beach you can walk along barefoot, not to mention passing one little open air restaurant after another. And on Ambergris, these beach front restaurants are mainly intimately small with quietish crowds and only some playing entirely tolerable levels of music. Some even have inviting bars opened right on the beach. If there's a scene like this in Cozumel, and there might very well be, I missed it when I was there.
If you do go to Ambergris, you might just want to live on the Pupusas--try the moringa one, if you don't mind waiting a bit while an older lady goes off into the backyard to pick the moringa leaves for you.
