[wizwazzle]

I'm an underwater photographer. You're not wrong, but here's the thing, the deeper you go, the less light is present and the reds get filtered out. My fingernails and hands at 60ft down look purple. So editing is a must. Here's a good overview of a common underwater photograph practice: http://diveadvisor.com/sub2o/get-your-white-balance-done-rig...

It's the equivalent of telling someone to pose facing the sun so there's enough light shining on their face. We do the same thing but with strobes and editing, because when you're 100ft down, it's never lighter than twilight.

These Nat Geo photos don't look altered all that much. Good photographers will make subjects look as they do to the naked eye.