It's hard to judge distances based on an illustration, but Leviathan seems like an ambitious name for such a small vessel. By comparison to the Inn's 85' in length, the USS Constitution was 175' at the waterline, and almost 45' wide. By contrast, the Leviathan is more the size of a large caravel like Columbus' Pinta.

Another detail related to Waldonrate's commentary... the pitch of the roof on the extended is pretty steep, and the second floor would be crowded on the inside and outside walls by the roof. For practical reasons, the stairway to the second level would be on the inside of the room and not the outside wall where anyone coming up the stair would have to do battle with the rafters.

I think your map is excellent, technicalities notwithstanding. Have some rep!