I thought christa was asking about cave tubing. For that, I would stick with Ian Anderson, christa - like I said, he has received raves on this board from MANY folks. If Lan sees this thread, he could tell you more. I did find this article on caving with Ian. It also mentions Jaguar Paw and Banana Bank, with websites for all.
http://belize1.com/pages/town/article8.html