Indigo has an own atmosphere material, which he used, on this picture. The whole thing is basically *real* scaled
water is harder. But I doubt, you'd see any wave patterns from that distance
Also the clouds should look pretty flat from this distance Just the ground might show differences in reflectivity... That might be true
That "believable atmosphere", you see on renders is far too strong, in most cases
- in fact, it usually is barely or not at all visible, as it is here 
) would be soooo cool