If you haven't heard of
Hydro Zorbing before have you heard of
Aqua Sphereing?
Even if neither name rings a bell, Aqua Sphereing probably gives a little bit more away. Obvious from both titles is that there's water involved here somewhere, but the sphere in sphereing, suggests something round.
The round thing it's referring to is a giant, inflatable ball, made from two layers of clear plastic: something akin to what the designers of the James Bond films might come up with if asked to think of an emergency rocket escape pod. You, as the person going zorbing or sphereing, gets into said clear, inflatable ball, along with a decent amount of water of variable temperature, and possibly a mate or two, and off you set, tumbling down a preprepared track, or just freestyling it down a hill.
By Flickr user Jonathan_W
In theory the water acts as extra padding and you don't actually loop the loop with the sphere, otherwise there would end up being more than water in the ball by the end of it. In practice its actually fairly effective.
The whole roll usually lasts about 30 seconds depending on the course.
By Flickr user Jonathan_W
The people who designed this 'experience' say it's the closest you can get to knowing what it feels like to be in a washing machine. And people who've experienced it would agree.
Some recommendations are that you only enter your sphere with bodies you're not going to mind getting tangled up with – and exclude any of your friends with particularly sharp knees or elbows.
You want a nice rounded chum for this one. About 30 litres of water goes into your ball, which is quite a lot. It can also be quite cold.
These pieces of information aren't here to put you off, I've just trying to prepare you for it more than I was.
FYI: Zorbing and Sphereing started in New Zealand, but there are now plenty of places where you can try it dotted all over the country.