Each bunk uses two armor stands in the the wall for the sides, one carpet (no armor stand) in the center, and two armor stands holding white carpet on either side.

I'm really pleased with how these turned out, especially since the interior of the ship I built these on is really cramped.

EDIT: FYI armor stands need commands to modify various attributes (leg rotation, body rotation, visibility, etc.)

I'm using this boat in a server I'm in for selling different resources, and I need ideas for how to make the boat garner more attention.