I believe I did have a similar effect back when my material was Opaque, however I have since changed it over to translucent and no longer get the same look. But from what I recall it does look very similar to my original material. Adding in panning normal maps with small ripples will help disguise , and will make the waves look much more realistic.
Some other points to consider:
- Use a fresnel hooked up to the alpha of a lerp, with a dark & light base color input into A & B, input the result of your normals into the Normal slot of the fresnel, and use a scalar parameter to adjust the Exponent
- Play around with the specular and metallic levels as well, these can increase the reflection on the waves
- Try adding a movable skylight if you are using dynamic lighting, it can also add to the reflections
- Try changing the time of day to see if the dark spots change location, also go into your PP and make sure the SSR settings are 100% quality, defaults to 50%
I have 3 videos of my ocean on the link to my WIP thread below, the dark spots aren’t really noticeable, but I believe is mainly due to the surface being rippled by the normal maps, hiding the effect. I they don’t go away after adding in the ripples, then there may be an in the calculation, but I wouldn’t worry too much right now.
By the way, if you are planning to make your material translucent, be sure to have a look at Thread there are some issues with translucency currently.