For Caye Caulker I would recommend Carlos Eco Tours located on Front Street next to the Sandbox, Juni's Sailing Snorkel Tours also on Front Street across from the basketball court, or Raggamuffin Tours located on Front Street closer to the split across from Blue Wave Guesthouse. For diving, definitely Paradise Down Scuba or Belize Dive Services.
--Lee
www.caribbean-colors.com
www.cybercayecaulker.com