We went tubing last year in Ocho Rios. We were on RCCL at the time and they did not have a tour so we did it ourselvs. We took a taxi from the pier to the White River, about a 20 min. ride. It cost us a total of about $25-30 per person ( that included taxi and tubing). Any questions please feel free to e-mail me.
We did the Tubing Safari in Jamaica last week it was alot of fun would recommend it but not if you have young children who are not very confident in the water, it is easy in a few places to be tipped out of your tyre type inner-tube and it is not possible to be together in your group all the time. The people were friendly on our tour and the views were lovely, you stop of after for a drink at the end of the tubing bit on your way back to the ship this was a bit basic to say the least we stopped at the side of a dirt road some local families were doing their washing in the river but you got to see how the locals must have to live. The river was very clean and when the water was shallow you could see the bottom although it is deeper in places i would not have noticed this if one of the guides hadn't climbed a 20ft tree and jumped into the river. There is a few places where the river dips down and the water swirls around and this you go single file and may find yourself spun round in circles due to the current (this is where you would tip out if you were going to) but a guide is always close by to help you back into your tube. It is alot of fun and there is nothing dangerous with teeth in the river, they also video the group as you make your way down the river and take photos which you can buy.