Jake (oarboatman) and I built this feature into the frame on my boat, using the hatch cover (center) and the two nesting tables to provide a 48-66" x 72" sleeping platform. The daughter frame on the right side of this photo contains a table, and another we built another, shorter, table that will cover the footwell. It doesn't take long to reconfigure the boat into sleeping mode.
After a little bit of experience, we found it easier to sleep on the boat with the tables swapped, so that there was support for the woman and I to put our feet on each side of the cooler and our heads towards the bow in a "Y" config. The dog was quite happy with this arrangement as well.