There is no guide, except at the spot where you have to get off before the rapids. You have to walk about 1 mile to arrive at the tubing station. As for the tubing itself, it depends on the winds and other things but I'd say about 1 hour...
You can take as long as you like on the tube. No specific time limit
The tube you go by yourself you can take as long as you like or as quick as you wan't to and it isn't guided.
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