Just got back a couple of weeks ago. There are a lot of opportunities depending on what you are looking for. I believe The Moorings has a base on Ambergris if your looking for a full fledged
charter, otherwise there are quite a few local outfits that will take you out for a day or half day of sailing/ snorkeling/ and
fishing. JUst ask around when you get there. Have fun, I wish I was back there now.
Dave