Portland Boat Mattress has made the process simple and easy. First, remove the old mattress and lay the pattern sheet into the bed frame:
|It's a little hard to see the marker lines in this photo but they are there.|
video. The pattern is shipped back and a new mattress arrives few weeks later. They even called us and our marina office a couple days before the mattress arrived to let us know the expected delivery date -- very helpful!
After wrestling out the old mattress:
And the hinge works like it's supposed to work: