Memory foam is memory foam, I'm not aware that there is a marine variant. If you search for memory foam on the net there are thousands of links. We bought some from the States and it's worth considering whether you want a 'topper' or a complete mattress. Also you get what you pay for - low density is cheap, high density expensive. There are lots of sites explaining the options.
One issue is that it tears easily, so if you take the bed apart often to get to (say) a locker it will split.
They have a vast database with sizes for all kinds of boats.
Just hop across the Northsea to collect them when they`re ready. They have a shop in Medemblik marina.
I bought a mattress topper (2") in its own cover from my local bedding shop. as cheap as any of the other offers I have seen. makes a big difference to the comfort level.
sleepdetox, Welcome to the forum, I hope you will take your place in this community with your specialised area knowledge, in much the same way as others here.
As a first (and second ) post This is just a bit overtly self serving, no?
Please do not recommend yourself, as self praise is no recommendation, and this really isnt an area for free commercial advertising. Discreet URLS have been accepted most of the time.
The forum is usually very grateful for hints and tips on the subject at hand and we would really welcome you joining in with your experiences and problems too.