Snorkel of Cave Tube with no Reservations?

[Frisbee131313]

I will be in Belize on 11/26, and it will be the 4th stop on our cruise. I may still want to snorkel (shary ray alley), but I might want to cave tube to mix it up instead. Is it possible to get off of the boat early and book with a local place on the spot, without advanced reservation?

[Frisbee131313]

Is it possible to find ***** when you get there and book on the spot? We are meeting other couples on the cruise, and will decide on the excursion together... which is likely to be cave tubing.