A sleep system employing a water-filled vinyl bladder as its primary support system. Original models relied on rigid framing to contain the vinyl components and were known as a “hardside”. Newer styles consist of vinyl components (bladder and liner) typically encased in foam and made to look like a conventional mattress, usually paired with a regular upholstered foundation. Also called a “softside” waterbed. All versions are sometimes referred to as “flotation beds.”
