Deep Fill Softside Fluid Beds | 8″ to 9″ Depth: Deep Fill fluid beds use a 8 inch – 9 inch water chamber to float the body and displace the sleepers weight and pressure to create a supportive sleep surface that rivals in comparison to the support and comfort of a traditional wood frame with the clunky box frame. Giving the sleeper the ability to transition out of wood frame waterbed furniture and linens but still benefit from the comfort and support of a true full depth waterbed sleeping experience.