Having just logged in to the forum whilst I'm here at work, I can't believe what I started by mentioning my waterbed! Just for the record, so as to avoid any confusion, waterbeds are actually graded 1 through to 6, 1 being the wibbly wobblyest of them and 6 being quite firm. I had strong reservations about having a waterbed, but after lying on one with the sales assistant lying beside me and the kids jumping up and down on the end, my mind was changed and the waterbed arrived a few weeks later. We had grade 5 king size with soft sides. To look at it is just like any other divan. There is no roll together and no waves either. Some 8 years later I definately recommend