I know it’s known about water being dark from about 8 blocks away. However, theres a vice versa where if you’re looking at water i.e., a river from say a hill or mountain top, you can see through all the water, showing all the not so pretty patches of dirt, gravel, sand, clay, etc underneath.
Side note. Water seems to have a weird ghosting effect when being viewed while moving horizontally. (A waterfall)
This issue is being tracked at MCPE-203239.