Which type of draft mark indicates the operating draft?

• A. Calculative
• B. Limiting
• C. Navigational
• D. Plimsoll

Answer: (C)

Operating draft is the ship’s current depth in the water under its present load. The marks used to show this are navigational draft marks, etched along the hull at regular intervals so you can read how deeply the vessel sits in the water by noting which mark aligns with the waterline. These marks move with loading and unloading, giving a real-time indication of how much of the hull is submerged, which is essential for safe navigation and avoiding grounding.

Plimsoll marks, by contrast, indicate the maximum load line for different water densities and seasons, not the actual current draft. Calculative marks are used in loading calculations to determine how much weight can be added, and limiting marks indicate maximum permissible draft under certain conditions but do not reflect the live operating draft.