I had a thought ( I know, those are rare)You might try a few squashed spheres, or a solid terrain with a volumetric cloud material at the edge of your water to simulate breakers. I tried this in a scene and it seemed to turn out well, judging from comments. I like your scene in progress and I think your water material and lighting are perfect for the scene. And if I were on that ship I'd be dropping all anchors and furling those sails in a hurry!