The hell does this mean?

"It's a little bit like sand, but with water on top."

Someone said this somewhere and I have no idea what it's supposed to mean.
Anyone know what that means? or have any ideas?

I'm not sure about that. I think it's some shitty old saying that's supposed to mean something else.

Ex: The grass is always greener on the other side.
Mening, the way we tend to look at other people’s lives and other things that we don't have in general.