If you are referring to the Martha Brae River Rafting, that is not "river tubing", but on actual bamboo made rafts which are propelled by a standing guide. This appears to be a very relaxing tour, but at one time, there were problems of tourists being robbed. This is just hearsay, so if it interests you I would definetly check it out. The major cruise ship's would not continue offer this tour if it were dangerous to the passengers. If you have never visited Dunn's River Falls, this is a beautiful site to see.