The second factor in the 3-part puzzle is that water adapts to the shape of the boat, bathtub or person it contacts and it does in proportion. Your torso is bigger and heavier than your hips - on a waterbed, that's fine because the bed just accepts the shape you are and most importantly it doesn't stress that shape by trying to change your posture to match it - the bed moulds to you to such a degree that even pregnant ladies can lie on their tummies! Back pain sufferers find great relief and comfort on our beds as they are not lying on an un-yielding mattress which doesn't emulate the curves of their spine. Often people comment that their legs feel higher when they lie on our beds - strictly speaking it is that your back is lower, not your legs higher; because it's heavier, it sinks deeper into the bed. This means your posture remains correct as the top of your back does 'stick out' further than your backside!
If you adopt a blank canvas approach it’s just so simple to see the tremendous benefits of this unique bed over every other sleeping surface.