This would be a nice "natural" evolution for BeamNG. We already have really good still-water physics, but the waves unfortunately are visual only. Would be nice to have for those vehicles that can already float, and of course the few boat mods that are available.
rigs of rods had water physics so idk why they decided to not include it in beam. the wydra and boat mods would really benefit from this, and while they're at it they can also add reflections to the water
I am persuaded it is already on the dev's to-do list, just not a top priority for the moment (maybe soon if I had to guess)
I think you'll like my new mod. it's been in active development for a while now and will be ready soon)