Ships are built in horizontal layers. A deck is a horizontal surface on a ship that forms a floor or roof for the spaces above and below it, providing structural strength and working area.

The main deck, weather deck, and various ’tween decks each serve different functions. Open decks carry cargo, equipment, and crew movement; enclosed decks form accommodation and machinery spaces. Deck strength limits the weight of stacked containers or heavy lifts.

Non-skid coatings, drainage, and securing points are practical details that affect safety. Working on deck in heavy weather requires life lines, careful timing, and constant awareness of green water. Deck maintenance—chipping, painting, and inspecting for cracks—is continuous work for the crew.

• Horizontal structural and working surface on a ship
• Includes weather decks and internal decks
• Carries loads, equipment, and personnel
• Requires strength, drainage, and securing arrangements