Abstract: A watermattress includes a plurality of elongated water-filled tubes in a suitable frame, and each tube includes a wave dampening insert of foam or fiber. A base strip made of a substantially flexible material, such as vinyl, is fastened to each end of the tube. The wave dampening insert is fastened at a plurality of places along the length of the insert to the base strip, whereby the insert is substantially incapable of sliding or moving around in the tube even when one end of the tube is lifted. The foregoing feature prevents the insert from becoming dislocated and distorted in the tube as a result of extended normal use of the watermattress or even when the tube is moved or lifted for the purpose of draining, filling or moving the watermattress, and thereby makes the watermattress user friendly.

Abstract: A tube-type watermattress has a plurality of elongated tubes disposed in a head-to-toe direction in the mattress. A wave dampening insert enclosed in each tube has a center portion which is substantially thicker than the rest of the insert to provide additional firmness and "lumbar" support in the area of the mattress where the lower back or "lumbar" of a person resting on the mattress is usually disposed.