raart

I have been to Belize on multiple occaisions and I am sad to report that there really are not good beaches on the mainland or the cayes. The snorkeling is if not the best among the best in the carribean. The reef off of Belize is the second largest in the world. I can't imagine any excursion you will take snorkeling will be bad. But you will not find nice beaches. The reef is a mile or so off sure that is why the ship anchors so far from shore and tender rides of 20-30 minutes are required to get in to the port. I have taken independant exurcsions there and the down side is you must tender into the port then get on another tender and ride 30 minutes back out to the reef to snorkel. The advantage of the excursion through Carnival is most will leave straight from the ship to the reef saving alot of time and effort.

I am not sure which ship you will be on but if it goes to Roatan then that is where you can get nice beaches and great snorkeling.