An afterdeck is the part of a ship's deck amidships towards the stern. Italian ship-rigged vessel Amerigo Vespucci in New York Harbor, 1976. ... A permanent covering over a compartment or a hull[1]. On a boat or ship, the primary deck is the horizontal structure which forms the lid of the hull, which both strengthens the hull and serves as the primary working surface. ... For other meanings of the term, see Stern (disambiguation). ...
Now, I am sure there is some geek out there that would love to translate this for me. But in the meantime, I do not have the time, nor the desire to stop and figure this action out.
and "afterdeck" is a part of the ship towards the stern (or rear, i believe) of the ship.
afterdeck is: The part of a ship'sdeck past amidships toward the stern.