....I'd rather be slightly dehydrated than be forced to hydrate the aircraft seat on a 4-hour nav. Have you read exactly how much you have to drink to keep yourself completely hydrated?? Landing with your legs crossed (should such a position even be possible) may be dangerous too you know.
More seriously though, I actually did read a little about that. I take gatorade/powerade/fanta up with me when I fly now...I don't dare drink the whole bottle but if I start to lick my lips then I figure it may be time for a little bit of sugar water.