Those little things don't look like you wold be able to walk on top of water with them, and I am thinking that it would take a very light, and agile, person to even come close; which is probably why it was only done by a Ninja, who would have excellent balance, and flexability.
Even so, I think they look like they would do better with kind of sliding your way through shallow rice paddies than trying to actually float in them, and would undoubtedly be quieter than sloshing your way along.
We had eliminated about everything else there was to guess, so it was not so much a good guess, as it was the ONLY one left, but thank you for the cheers, in any case...