I just wanted to post a quick recommendation for Reggie Tours in Belize City. If you are going, look him up on the internet and book an excursion through them.
We arrived in Belize and went to the arranged meeting place and we became worried when Reggie did not show up at the meeting place. (we later determined that we were booked for 2007 and not 2006!) Luckily we had an email with their contact information. So we were able to contact Reggie and he quickly arranged our cave tubing tour and saved the day! Even though we started about 2 hours later than planned, Reggie was able to give us a great tubing experience and still got us back to the port with time left over for the girls to shop! Our tour guide Lionel (and his assitant Lionel..must be a popular name in Belize) were outstanding! They provided a lot of information about Belize and the local wildlife during our walk to the river. This made the experience even more enjoyable.
While tubing out of our second cave system, we saw where the tour from the ship booked excursion was starting their tubing trip and where they would have ended and to say the least, we would have been VERY upset if we had booked with them. We would have paid twice as much and had a much shorter tubing trip.
I wouldn't hesitate to book through Reggie again, and they offer other tours as well (Mayan ruins, shopping etc..)
I posted the cave tubing pictures to my smugmug site. I have a couple of video clips (my sister has a waterproof digital camera) but I need to edit them a bit before I post. But you can see what you are getting into if you look in the Cave Tubing gallery here.