Specifically, 浪 (which has the connotations of wandering, and is the rô of rônin) is used when the ship advances by cutting through the waves, while 波 (which seems to be used strictly for just a wave) is used for what the red sun rises out of and sets into. Both are read as nami, "wave," but yes, a shading of meaning.

And having tracked these down, I have a better chance of remembering them next time. (Ha.)

---L.