Common Ship Hull Markings

Common Ship Hull Markings

The most common hull markings on a cargo ship include:

  • Registry flag. The name of the country of registry.
  • IMO Number. The unique ship ID is registered with the International Maritime Organization.
  • Pilot Boarding Mark. The location where pilots can board the ship with the midsection of the marker at 9 meters from the freeboard.
  • Draft Lines (FWD and AFT). Indicators of water depth above the keel. Provides a visual indicator of the draft and the ship’s balance.
  • Load Line (Plimsoll Line). Indicates the maximum safe loading depth under different water conditions (saltwater, freshwater, summer, and winter). The summer load line is usually the reference.
  • Classification society. The summer load line and the acronym of the hull classification society.
  • Tug Marking. Indicates where tugboats can push to assist in maneuvering the ship. It represents a point of high structural integrity, such as a bulkhead.
  • Bow Thruster. The location of the bow thruster.
  • Bow Marking. The structural alignment and identification of the underwater bow.