The ornamental design for a bunkbed for a marine vessel, as shown and described.
FIG. 1 is a perspective view of a bunk bed for a marine vessel, showing our new design. The perspective view is taken from the front of the starboard side of marine vessel.
FIG. 2 is another perspective view, taken from the rear of the starboard side of the marine vessel.
FIG. 3 is a rear perspective view thereof.
FIG. 4 is a top view thereof.
FIG. 5 is a rear view thereof.
FIG. 6 is a view of section 6-6, taken in FIG. 3; and,
FIG. 7 is a view of section 7-7, taken in FIG. 7.
The broken lines in the drawings illustrate portions of the bunk bed and marine vessel that are not part of the claimed design.