Which draft mark type would you consult to calculate displacement?

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

Answer: (A)

Calculating displacement relies on how deeply the hull is submerged, which you determine from the draft. Draft marks show that immersion depth, and the type used for performing calculations is the calculative draft marks because they’re specifically provided for hydrostatic and displacement computations. The Plimsoll line, by contrast, denotes the maximum permissible static draft for loading and is a safety/load-limit reference rather than a tool for calculating submerged volume. Navigational marks guide routing and do not feed displacement calculations, and limiting marks indicate operational limits rather than the data needed to compute displacement.