(original, not S2):
Stern cabins: 2 mattresses, each 200 x 75 cm at widest point.
Front cabin (we have only one but the double front cabin are identical):
Two mattressses, although differently tapered than the mattresses in stern cabins, the sizes are identical. I. e. 200cm long and 75 at widest point.
We use separate sheets, i.e. 2 sheets for each berth. It is easier to manage and wash.
We use special rubber tensioners under the mattressees to keep the sheets tight.
I do not see how to attach a picture to the post on a phone