This is the Neva River in st. Petersburg, and they organized a "Walks on the River" event as part of celebrations of the 300th anniversary of the founding of St. Petersburg.
That's all well and good, but the point is... I want one! Finally we get to be the hamsters in the little hamster ball!
Plus, we get to walk on the water, which ought to be a cool new way to get to work. Unfortunately one couldn't use it to get to work if work was upstream...
Bonus: it would be weather-resistant, as long as it didn't get a hole somewhere. Hmm, you'd have to carry a patch pack and not wear anything sharp.