This waterbed mattress is very plush with moderate motion when properly filled to the top of the side rails. The Textured TOP Sleep Surface has a special low tension molded top that reduces surface pressure between your skin and the mattress surface. This creates an abundance of mattress surface area, allowing your body weight to disperse across the mattress better, without raising the water level. The Lumbar area is 24 inches long and is 15 inches from the top of the mattress.