In some respects, a ship is like a building, having floors (decks), ceilings (overheads), corridors (passageways), and stairs (ladders). But there are other parts of a ship that are unique and have their own terminology.
The hull is the main body of the ship. Metal shell plating forms the sides and bottom, and the weather deck or main deck forms the top. Where the sides join the main deck is called the gunwale (rhymes with “funnel”). The outermost layer of plating and decking is called the skin of the ship.
The shape and construction of the hull depend on the type of ship. Ships designed for high-speed operations—such as destroyers and cruisers—have long, narrow hulls with fine lines. Aircraft carriers and auxiliary ships have hulls with square center sections, vertical sides, and flat bottoms for greater carrying capacity. Submarines, designed to operate underwater, have hulls that are rounded, like an egg, because that shape withstands great pressure.