Bunk in a ship is a term used to describe the sleeping arrangements on a boat or ship. A BERTH is a BED or sleeping place, usually on a boat or ship, and is typically 5 letters long. A BED is a piece of furniture used for sleeping, and is 3 letters long. A COT is a small BED, often used for camping, and is also 3 letters long. All three terms can be used to describe the sleeping arrangements on a boat or ship, commonly referred to as a bunk in a ship.