Tidus has a magical ring which he uses to control the wind. He blows
papers in people's faces and stuff so that they don't pollute Spira. With his
four friends' powers combined they create Captain Gaia, a clean cut stud
in crazy colored spandex who flies around and does other awesome things.
In order to spin in mid-air, Tidus used his wind powers. In order to swim so
quickly, Tidus cheats by having his friend with the water ring move the
water around him and create a stream which he just floats in.

I just thought of this now actually...people are debating how the
characters can be underwater for such a long time. But shouldn't the
better question be, how the hell is there a giant floating sphere of water
in the middle of an arena?

Anyway, they do hold their breath. For proof of this, look at all the
underwater parts in the game, there are only 3 people who can go
underwater, and they can stay there for a damn long time. The others
haven't trained so they can't hold their breath for as long as those who
have.

.opt