Here, instead, are the next 2 steps of my painting. In the second one, I've gone over the existing colors at the very bottom with a wash of Winsor & Newton Payne's Gray and W&N Indigo (not over the whole thing, just where I wanted it darker). I'm hoping you can see the difference (?).
For now I'm happy with the result. I always reserve the right to go back in there at a later time. Next step: darken that next section right above the bottom wave to make the wave pop out. The white of that wave is NOT done. I needed some darks around it, in order to judge what to do next. (Maybe I'll figure out how to create that GIF as well! Any suggestions as to a good program to use?)