... excellently in material functions, but cheaper.2), generally, how long can people stay in the water ball?a). ... least every 30 minutes3), HOW DO YOU GET INSIDE OF THOSE BALLS?We have a zipper!4), HOW DO I BLOW THEM UP ... ; inside the "zorb inflatable ball" you can see fish as you're floating around on top of the ... , balance, endurance, and its fun, but if you need a work out walking and controlling the water ...