This is great, but this approach will break down a bit for REALLY big waves as they become non-linear. Water waves are not sinusoidal, but are close enough for small and medium wave heights that these methods work really well. The big big waves are not only much farther from sinusoidal but the waves start interacting with each in a non-linear way that can't be captured by the linear superposition approach used here.

So for most sea states, this is fantastic. But if you want to do the 'perfect storm' wave or something like that, you need to use a different approach for realism.