What is the outer diameter of the Plimsol mark on a vessel?

The outer diameter of the Plimsoll mark on a vessel is indeed 12 inches. This mark is crucial for indicating the vessel's safe loading line and assists in ensuring that the ship is not overloaded. The Plimsoll line is designed to provide guidance for the safe operational state of the vessel in various water conditions, distinguishing the maximum load level.

The diameter of 12 inches is standardized across vessels, which means that regardless of the ship’s size or type, this measurement remains consistent. This helps crew members and port state control inspectors easily identify if a vessel is loaded within its safe parameters.

Understanding this standard is critical for compliance with international regulations concerning vessel safety and load management.