Naruto Shippuuden Episode 86-87

[Azonalanthious]

Shout aside, I suspect it wasn't a fully formed rasengen in that case. The effect was similar to when he used one aspect of his rasengen training to create a whirlpool back in the race arc and I suspect that was basicly what was happening here as well. Rather then containing the spin in order to accelerate it and concentrate it, he simply generated the spin then released it into the water to form the vortex. Since, according to the inital training, his containment had to have every bit as much force as what he was putting into the spin, he is essentially leaving out a full half of the technique, rendering it much easier and so reasonably usable with only a single hand.

[Crash]

Shout aside, I suspect it wasn't a fully formed rasengen in that case. The effect was similar to when he used one aspect of his rasengen training to create a whirlpool back in the race arc and I suspect that was basicly what was happening here as well. Rather then containing the spin in order to accelerate it and concentrate it, he simply generated the spin then released it into the water to form the vortex. Since, according to the inital training, his containment had to have every bit as much force as what he was putting into the spin, he is essentially leaving out a full half of the technique, rendering it much easier and so reasonably usable with only a single hand.

Looking back at the episode it seems like what he used in conjunction with the water technique was in fact a wind element rasengan. Not only does he shout Futon: Rasengan (Wind Element, Spiraling Sphere) but the animation of it looks the same as the one they showed him using against Kakashi in the flashback. So it appears it was a legitimate fusion of wind/water jutsu and not just naruto spinning the water around with a half made Rasengan. Makes more sense that way anyway. If Kakashi's water barrier couldn't stop a wind/fire element combo i don't see why naruto simply spinning a water jutsu around would.

If he can throw it or not is debatable. The animation, though vague, seemed to hint at it. A regular rasengan can't be thrown, but it would make sense if a wind element one could.

[Buffalobiian]

Shout aside, I suspect it wasn't a fully formed rasengen in that case. The effect was similar to when he used one aspect of his rasengen training to create a whirlpool back in the race arc and I suspect that was basicly what was happening here as well. Rather then containing the spin in order to accelerate it and concentrate it, he simply generated the spin then released it into the water to form the vortex. Since, according to the inital training, his containment had to have every bit as much force as what he was putting into the spin, he is essentially leaving out a full half of the technique, rendering it much easier and so reasonably usable with only a single hand.

Only thing wrong with that theory is that back in the race arc, he concentrated on one thing: Chakra spin.

Futon: rasengan implies wind elemental manipulation, which he can't do simultaneously, hence his necessary two clones when forming the Rasen Shuriken.