We are travelling to Roatan, Belize City, Cozumel and Great Stirrup Cay, which stop is best for snorkelling?

Of your options I have snorkeled at Belize and Cozumel. Saw more fish and had more fun in Belize. Since this is a tender port and the ship is really some distance from shore, it was nice the boat picked us up and returned us to the ship and we cut out this extra "boat ride". We went to a little tiny island (not much more than a sand bar on the reef) but could go "ashore" and do breaks. There was a floating bar there also (seemed to have been run by locals--cash only) the reef and fish were amazing. Fun at Cozumel too, but there is lots of other stuff to do there and cave tubing and snorkeling are about the only game around in Belize.

Hi webber, welcome to Cruise-Chat. We just returned from Roatan and had a wonderful sail/snorkel excursion that we booked through the ship. The water was very clear, but the currents were a bit strong if you're not a good swimmer. Belize has some good snorkeling as spoheat states. There's some good snorkeling in Cozumel and in Great Stirrup Cay. If you're just wanting to book one or two snorkeling excursions, do them in Roatan and Belize. You can get a cab and go to Chankanaab Park or Paradise in Cozumel for some pretty good snorkeling from the shore. Great Stirrup Cay can be snorkeled from the shore as well. Best wishes for a fantastic cruise and once again, welcome aboard!