I looked into going to Caye Caulker when we're there in April 2005. The only info I could find was to use the water taxi. Its a 45 min trip each way. By taking the earliest water taxi we would only be able to spend about an hour and a half there before we would have to catch the water taxi back. I read another post where someone went and said they just didn't have enough time. I did fine a tour company located on Caye Caulker that you can contact called Star Tours. I'm not sure if they would provide just transporation back and forth to Caye Caulker. We decided to take the ship tour to Goff's Caye.