A cabin or berthing is an enclosed space generally on a ship

Ship

Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

 or an aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

. A cabin which protrudes above the level of a ship's deck

Deck (ship)

A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface...

 may be referred to as a "deckhouse."

Sailing ships

In sailing ships, the officers and paying passengers would have an individual or shared cabin. The captain

Captain (nautical)

A sea captain is a licensed mariner in ultimate command of the vessel. The captain is responsible for its safe and efficient operation, including cargo operations, navigation, crew management and ensuring that the vessel complies with local and international laws, as well as company and flag...

 or commanding officer

Commanding officer

The commanding officer is the officer in command of a military unit. Typically, the commanding officer has ultimate authority over the unit, and is usually given wide latitude to run the unit as he sees fit, within the bounds of military law...

  would occupy the "great cabin" that normally spanned width of the stern

Stern

The stern is the rear or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship. Originally, the term only referred to the aft port section...

 with large windows. On a warship it would be separated from the rest of the ship, and further subdivided into daytime and night-time cabins with movable panels that could be removed down in time of battle to leave the deck clear the whole length of the ship.

Modern warships

In most modern warship

Warship

A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...

s the commanding officer has a main cabin, the in-port cabin, often adjacent to the ship's central control room (operations room), and a sea cabin adjacent to the bridge

Bridge (ship)

The bridge of a ship is the room or platform from which the ship can be commanded. When a ship is underway the bridge is manned by an OOW aided usually by an AB acting as lookout...

. Thus, when likely to be called from sleep or attending to administration, the CO can be at the Bridge or Ops room instantly. The sea cabin is sparsely equipped, containing just a bunk, a desk, and basic toilet facilities. The in-port cabin is more lavishly furnished, with separate bedroom and combination sitting room/office, and more elaborate toiletry facilities.

For ships intended to act as flagship

Flagship

A flagship is a vessel used by the commanding officer of a group of naval ships, reflecting the custom of its commander, characteristically a flag officer, flying a distinguishing flag...

s, like the aircraft carrier

Aircraft carrier

An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

 the USS Lexington (CV-16)

USS Lexington (CV-16)

USS Lexington , known as "The Blue Ghost", is one of 24 s built during World War II for the United States Navy. The ship, the fifth US Navy ship to bear the name, is named in honor of the Revolutionary War Battle of Lexington...

, the admiral also has a sea cabin (adjacent to the captain's sea cabin) and an in-port cabin, in addition to the captain. Admiral Fletcher's sea cabin in the USS Yorktown (CV-5)

USS Yorktown (CV-5)

was an aircraft carrier commissioned in the United States Navy from 1937 until she was sunk at the Battle of Midway in June 1942. She was named after the Battle of Yorktown in 1781 and the lead ship of the Yorktown class which was designed after lessons learned from operations with the large...

 in the Second World War had a bed, an easy chair, a table, and a shower.

In the Star Trek

Star Trek

Star Trek is an American science fiction entertainment franchise created by Gene Roddenberry. The core of Star Trek is its six television series: The Original Series, The Animated Series, The Next Generation, Deep Space Nine, Voyager, and Enterprise...

 science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 series, the captain's sea cabin is called his "ready room". (On real ships, the ready room

Ready room

A ready room is a room on an aircraft carrier where on-duty pilots "stand by" their aeroplanes. Each flight squadron has its own individual ready room. Large squadrons, such as torpedo and dive-bomber squadrons, can have more than one ready room...

 is in fact where flight squadron pilots "stand by" their aeroplanes.)

Officers will normally have their own cabins, which doubles as their office. Some senior petty officer

Petty Officer

A petty officer is a non-commissioned officer in many navies and is given the NATO rank denotion OR-6. They are equal in rank to sergeant, British Army and Royal Air Force. A Petty Officer is superior in rank to Leading Rate and subordinate to Chief Petty Officer, in the case of the British Armed...

s may have a cabin for similar reasons.

Passenger ships

In ships carrying passenger

Passenger

A passenger is a term broadly used to describe any person who travels in a vehicle, but bears little or no responsibility for the tasks required for that vehicle to arrive at its destination....

s, they are normally accommodated in cabins, taking the terminology familiar to seafarers. First class cabins were traditionally referred to as staterooms, and today many cruise lines now prefer to refer to passenger cabins as staterooms or suites.

Spacecraft

In ships going into space the cabins are required to fully supply food and Oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

for their crew. On missions lasting a year or longer the cabins have to be self-sustaining, i.e. replenish their own water and oxygen. The space cabin for any long-range manned mission is expected to be reasonably spacious, with approximately 28 cubic metres allotted to each occupant. In addition cabins have life support systems that should have the capability to meet a variety of off-nominal conditions, including cabin fires, depressurization, and component shutdown or failure. Frequently these conditions occur so quickly that automatic
control systems offer the only possibility for recovery. Several experimental ground facilities have been developed to evaluate regenerative life support systems for manned space flight.