Yup. I don't think floating will be a problem, I haven't used much. Most of it is super glue and epoxy, just used the black foam to fill in some areas. The biggest spot with the foam is on that ramp in the back. I have to seal that off so none of the sand goes under the rest of the eggcrate and fills the cave with sand.
I was thinking of putting a few rocks under the ramp anyway, so I don't have to use ton's of sand to fill in that area.
I can't go to glass beach anymore, pisses me off. People sitting on the beach filling bags and containers with glass when you aren't allowed to take it. I will say they could increase the signage to try and stop this. You would only know you couldn't take the glass if you read it on the internet, or one of the general information signs when you first get to the park. But there are no signs around the stairs down to the beach.