People say that swimming is a good way to keep fit....

www.hotukdeals.com/item/454905/12ft-swim...ool-filter-pump-only

I was thinking, all you would have to do is put some kinda of waterproof-motor underwater to create some kind of vortex that caused a current you could swim through? Maybe that would work.

Who's with me.

We actually used to have one of those at uni.

errr... wasn't quite as perfect as the picture... it ended up flooding the house!