I've made some improvements to the beaches with the waves now applying buoyancy and wetness effects.
Waves actually apply forces on objects, so in addition to floating and rolling around, they will eventually wash up on the beach. Wind affects the wave size and turbulence too.
Objects hit by waves will get wet. Shorelines now have a visible waterline which rise and fall with the waves. In addition, waves will swell up when it hits a steep surface like cliffs. They also collide and wash over rocks near the shoreline.