The phrase "sand bottom" refers to a place, usually a body of water like a beach or a lake, where the floor or ground is made up of sand instead of rocks or soil. Full definition
Experience this small laid back surf community that hosts a tropical blue, right hand reef break and sand bottom beach break right beside each other. (wavehunters.com)
This varied surf beach is mostly sand bottom with rocky patches. (wavecation.com)
If you're looking for warm, transparent water, with a clean white sand bottom, this is the place. (mayanprincesshotel.com)