Abstract: A waterbed which is preferably substantially rectangular and has a substantially rigid base structure supporting a substantially rigid, but somewhat flexible, wall structure in which bladder means full of water is located so that the upper surface of the bladder is preferably about level with at least most of the upper edge of the wall structure. Liner means is placed between the bladder means and the wall structure in order to prevent leakage of fluid in the event that the bladder means is punctured. A zippered mattress cover is mounted upon the wall structure and covers the bladder means.