I have been pulling a tube from my tower for over a year. My friend has been pulling two tubes from his for over 3 years. Not one problem. As far as the pull from the tube while out to the side of the boat, it is minimal because by the time the tube crosses the wake, you are setting up for the next turn in the other direction. If your riders are subbing the tube on take-off, they need a lesson. I have never seen a tube sub while under way. Could you damage your tower pulling a tube? You sure could. Just as you could hurt your rider if you drive like an idiot. It just take a little common sense and technique.