You know I might as well ask here Can the Eldar swim? Do they find swimming beneath them? Do they find themselves beneath the ocean? Can they get their heads out of their own asses so they can get their heads above water? Do Eldar specialize in swimming?
One interesting thing however is that tanks such as Fire Prisms and Wave Serpents can hover above the water.
We can also hover above lava - I recommend Lava Moats - suck on that ground-trapped races To answer your question, we 'swim' on our Craftworlds quite often - but we do so through a unique mixture of anti-gravity thongs and a unique mixture of chemical compounds and ambient psychic energy flowing off our infinity circuits which allows us to swim through the sky. You simple races might regard it as flying, but due to the density of the atmospherics and the psycho-euphoric effects of proximity to the infinity circuit - the experience is much closer to swimming in both tactile sensation and motion: so your proclaimation of 'flying' was wrong before it was even uttered, are you not ever the fools! It's also worth noting that our Warrior Paths have no quarrel at all with swimming even in your filthy oceans, brackish rivers, nor even swimming through the torrents of Mon'keigh and Greenskin blood you seem so want to bathe us in: honoring Khaine sometimes involves lowering ourselves to the tepid conditions of the inferior races and their dismal planets - we need only to fix our hair before returning to the comforts of civilization. We bide our travel through the immaterium with hair-braiding parties and long baths.
