I got ride of the semi-transparency effect on the shores. It was a quick trick, it didn't look so good, and it'll eventually be replaced by a true refraction / fresnel effect.
Instead i decided to give a try to foam, blending between an animated foam texture and a pure white texture, then modulated by the waves, then modulated by the ocean depth ( basically the distance between the underwater surface, and the ocean level ), modulated by the sun color, etc.. That's a lot of modulations :)
I'm also now modifying the ocean base color by a small amount depending on this ocean depth too. The ocean color is dark blue-ish for deep ocean, and gets closer to green-ish near coastlines ( since most screenshots are near coastlines, you won't notice it in screens ).
I added back the high dynamic range pipe; it's looking pretty nice at ground level, but horribly saturated at high altitudes / orbital views. Still a lot of tweaking in perspective.
The foam texture is a "static" texture ( it's not procedurally generated ) and it's only 256^2, which is why it's obviously tiling. Will be fixed later once i generate a foam texture procedurally ( in 1024^2 ).
The waves patterns haven't been fixed yet ( if they can be fixed, that is, which is easier said than done ).
Those screens are in HDRI, it's slowing down quite a bit with everything on ( especially the x4 supersampling anti-aliasing ), i "only" get around 50-60 fps: