That cruise cal is great, isn't it? I can't take credit; I found it somewhere on this bulletin board and bookmarked it. I was **stunned** at Jaguar Paw when the guide said they sometimes have 1500 people thru there! It was way more fun to have the place to ourselves as we tubed.
Try this link for SeaDuced http://www.ambergriscaye.com/seaduced/
If you book at their office in town (big purple bldg) you get a free shirt. This was great for me because I followed the VERY WISE advice of someone on the BB who suggested I pack fewer clothes and more $. I needed the money but then I ran out of clothes! Well, clean ones, at least.
My piece of advice re: snorkeling and such--buy your underwater cameras before you leave. They are cheaper and one is not enough! So much to see!
Also, I rented my snorkeling gear from Ramon's (where SeaDuced leaves from) and it was fine. I think it was about $10.