In this setup I made the ship lighting come from a Nishita Sky Texture and the clouds + ocean reflection come from an HDRI by using the Light Path node.
But what's wrong is the transmission/reflection in the ocean. It should come from the HDRI instead of from the Nishita Sky Texture.
Here's how it looks with the setup I showed above (notice all the sand-looking transmissions/reflections coming from theNishita Sky Texture):
Here's how it looks when I preview the HDRI only (it should be like this but with the ship being lit by the Nishita Sky Texture instead, so that I can make the lighting more dynamic without affecting the ocean):
So, how could I make the transmission color come from the HDRI instead of from the Nishita Sky Texture? I've already tried the obvious stuff, such as plugging the “Is Transmission Ray” output of the Light Path node into another Math (Add) node, but it didn't work. I also tried tweaking the ocean shader: decreasing the Roughness to 0 removes the ugly reflections, but it makes the water look super nasty and over-processed. Any help would be really appreciated!