I've heard a lot of requests for accessibility for people with Thalassophobia, but I can agree that it's hard to implement it in a way that doesn't break the immersion of the game. I did however think of a quick idea that may not entirely remove the fear, but help players feel more certain about the depths of the ocean
What if players could enable a "ocean floor" that doesn't actually exist, but acts more like a skybox in the floor to provide players with Thalassophobia some comfort knowing what's at the bottom of the ocean. Since nothing really jumps out at you from there, I don't see why this would hurt immersion
