Didn't know you could stand on a tube, feel a new challenge compie coming on that could rival Broontroots unicycle 
Strikes me as being an activity restricted to folk built like racing snakes
which means I'm
never going to be standing up in a 'tube
I've way too much 'ballast' for me to give it a go
That said, most float tubes I've tried would probably be more stable than many a loch boat I've used in the past
H
