Re: Wakeboard/Ski Towers
A wakeboarder, kneeboard or skier will let go of the handle if overwhelmed by line tension.
In all of those activities, it is the RIDER'S responsibility/skill to manage slack in the line.
A tube is tied directly to the boat via tower/transom/ski pylon/tow eye - whatever. With tubing, it is the BOAT DRIVER's responsibility to manage slack in the line.
A multi-person tube is not only much heavier than any single skier, it can't let go of the handle. If the tube swings out to the side, slows down, falls below planing speed and sinks or comes to near stop... when the inattentive boat driver continues to motor on at 20 mph..... WHAM.
There is a momentary extreme load. (three adults + big wet tube = 500# easily) With the leverage of a tall pylon or tower on a lightweight boat, it is enough to rock the boat over hard (I've seen passengers thrown out of their seats by this) or bend and collapse ski pylons, or pull out mounting points. or give a pretty good case of whip lash to riders, break ropes.....etc.
If the driver is on the ball and understands the above distinction, towing a tube from a pylon or tower CAN be done at no risk to riders and equipment. I'm just not real confident in the driving skill of the general boating public.