Waterbed

A waterbed is a bed or mattress filled with water. Waterbeds intended for medical therapy date back to the 19th century. The modern waterbed was invented San Francisco in the late 1960s by Charlie Hall. It was patented in 1971. It became a very popular in the United States in the 1980s and 1990s.
Waterbeds are made of two types: hard-sided and soft-sided.