I see your hobby is snorkeling. If you're going to Belize for the snorkeling, it's not the best we've seen. Especially since you must go in a boat to get to any snorkeling. We did meet one couple who had rented a kayak at Captain Morgan, I think, and went out to the reef on their own. But the power boats are going very fast, and I'm not sure how safe it is to kayak, at least in an area where the boats might be coming & going.
We didn't go to Mexico Rocks, so maybe it's better than the marine preserve. It was overcast the day we wanted to go to Mexico Rocks, so didn't check it out.
The divers and fisherman seemed to like Belize, but for snorkeling we prefer Tahiti or Maui.