I might desaturate the ocean some, like the others noted. Just a thought about getting rivers to behave believably - you're doing okay at wiggling some curves into place, but a way to express what Midgardsormr notes might be the scale is partly off. Try doing your wiggles while zoomed in progressively more and more as you draw your way downstream. That could make "random one-inch hand movement" trace progressively tighter and tighter curves, like a mature river in flatlands developing loops and swirls.