Sorry - no knowledge on the item you are chasing - but you may find the solution in other places.
One possibility might be to look at futon mattresses. We have one (at home, not in the boat) that we use in much the manner that you describe. Another is to get a thermarest, which will go on top of anything and make a reasonably comfortable bed out of anything - and if your daughter is like ours, she will then take it all round the world wthe her. They ain't cheap, but they last forever and will make anything at all a possible sleeping area. Charley
