What is your final destination?
I am not a local just a one time visitor and a long time board lurker but here is the contact info for the airline that services the area
https://www.tropicair.comIn the US or Canada call: 1-800-422-3435
In Belize call: 011-501 - 226-2012
I also think there is a ferry but I have never taken it and don't know when they stop. Someone more in the know maybe able to help more. I hope that helps and have a great time.