Charles Prior Hall is the creator of the modern waterbed. In 1968, while he was a design student at San Francisco State University in California, he worked with fellow SFSU students Paul Heckel and Evan Fawkes to create the concept.
Hall originally wanted to make an innovative chair. His first prototype was a vinyl bag with 300 pounds (136 kg) of cornstarch, but the result was uncomfortable. He next filled it with Jell-O, which had an unfortunate "tendency to decompose". Ultimately, he abandoned working on a chair, and settled on perfecting a bed.
Hall was granted a patent on his waterbed, which he originally called "the pleasure pit", in 1971. He founded Innerspace Environments, a manufacturing and sales company which became the leading retailer of waterbeds in the U.S., with 30 owned-and-operated stores. Hall was unable to defend his patents against multiple competitors and couldn't take full advantage of the waterbed's subsequent popularity. Sales peaked in 1987 at 22% of the domestic mattress industry.