Deck (ship)

Decks are the main horizontal parts of a ship's structure. The crew stand and walk on the deck. A **deck** is the floor of a boat or ship, but open boats only have floorboards. 

## Common names for decks 
Below is a list of the many names given to different decks. They might be confusing. The list should be used with caution because there is no one agreed system for naming decks. 

* **01 level** is the term used to refer to the deck above the main deck. The next higher decks are referred to as the 02 level, the 03 level, and so on. Although these are formally called decks, they are usually referred to as levels. This is because they are usually incomplete decks that do not extend all the way from the stem to the stern or across the ship.
* **Afterdeck**: The deck closest to the stern. This is where the hammocks of the crew are slung.
* **Lido deck**: Open area, typically at or near the stern of a passenger ship. It usually has the main outdoor swimming pool and  area.
* **Lower deck**: (a) the deck immediately over the hold. Originally the term was only used on a ship with two decks. (b) synonym for berth deck. (c) alternative name for a secondary gun deck it is the lowest deck in a ship, but the Orlop Deck should not be confused with the tank top of a vessel with double bottom.
* **Poop deck**: The deck forming the roof of a poop or poop cabin, built on the upper deck and extending from the mizzenmast aft.
* **Promenade deck**: A "wrap-around porch" found on passenger ships and riverboats encircling the superstructure.  This can have open railings or be enclosed in glass, or a combination.  Often the entire level where this is located is referred to as the promenade deck. 
* **Quarterdeck**: (a) The part of the upper deck abaft the mainmast, including the poop deck when there is one. Usually reserved for ship's officers, guests, and passengers. (b) (*Naval*) The area to which a gangway for officers and diplomatic guests to board the vessel leads. Also any entry point for personnel.
* **Side-deck**: The upper deck outboard of any structures such as a coachroof or doghouse, also called a breezeway
* **Spar deck**: (a) Same as the upper deck. (b) Sometimes a light deck fitted over the upper deck.  On Great Lakes bulk freighters this is the term used for the deck over the cargo holds.
* **Sundeck**: A deck where people relax in the sun.
* **Sweep deck**: (*Naval*) The aftmost deck on a minesweeper, set close to the waterline for ease in launch and recovery of equipment.
* **Topgallant forecastle deck**: Any raised deck occurring above the forecastle deck (see above).
* **Tween deck**: the storage space between the hold and the main deck, often retractable.
* **Upper deck**: The highest deck of the hull, extending from stem to stern.
* **Vehicle deck**: (*Naval*) aboard amphibious assault ships the deck or decks used to carry vehicles, aboard civilian ferries and other commercial vessels a deck used for a similar purpose.
* **Weather deck**: (a) Any deck exposed to the outside. (b) The windward side decks. 
* **Well deck**: (a) An exposed deck (weather deck) lower than decks fore and aft. In particular it is one enclosed by bulwarks limiting flow of water and thus drainage.

## Freeboard Deck 
Ships over 24m long doing international business have to respect the International Convention on Load Lines. Such vessels have a deck named the Freeboard Deck. It goes from end to end in the ship and from one side to the other. Decks below the weather deck can be the Freeboard Deck, as in most ferries. The distance from the sea surface to the Freeboard Deck is named the freeboard. All these ships have a minimum freeboard. At no time may they be so deep in the water that the freeboard is smaller than the minimum freeboard. For that reason, the Freeboard Deck is an important reference point in the ship. Some shipyards and shipping companies name the Freeboard Deck as Deck 1 or 1st Deck. The decks below are 2nd Deck or Deck 2, 3rd Deck or Deck 3 etc. The decks over the Freeboard Deck have letters. The first level over the Freeboard Deck is Deck A. Over that is Deck B, Deck C etc. This system of deck names says where the deck is in the ship. This is important because the Load Line Convention has special rules about doors, windows, hatch openings and ventilation openings on Deck A and Deck B.

## References