Most vessels of that size (and larger) need to anchor just inside the cut outside Belize Yacht Club and then dingy in. AC is not the best place for a big boat like that. At one time there was a 70' liveaboard anchored behind Caye Caulker... How long are you looking to stay? 3.5" draft is pretty close to the maximum I would try putting up to a dock. Try calling TMM Charters or Belize Yacht Club for more info.
Your boat isn't that big. You can moor just offshore all along the beach and use a tender to go back and forth. There won't be many places to moor at a dock - for different reasons I wouldn't use either of the two mentioned.
The opinions and views expressed on this board are the subjective opinions of Ambergris Caye Message Board members and not of the Ambergris Caye Message Board its affiliates, or its employees.