Tubing was one of the funnest part of the trip. We lived in a dorm and had made a huge group to go with over there. We started drinking even before we started tubing And it was bloody awesome.
At first bar we were playing all sort of sports like volleyball, football, basketball, frisbee beer etc.. But by the time we reached second bar, it all got into drinking games and jamming etc stuff (by this time you are really drunk) and till you reach the third bar, you are just looking to do random stuff (or people ;)) and its even a struggle to get off the tube here.
I would say, make a nice group and go and keep on adding people there. Then it will be much more fun. There is not dancing there as the music is too low but by the time you reach back in eve, you would have had time of your life.
PS: Do return the tubes back to the company on time else they will keep back your deposit :)