A trimming moment can affect stability by changing which of the following?

• A. The forward-aft draft difference (CT)
• B. The ship's weight
• C. The hull length
• D. The water displacement

Answer: (A)

A trimming moment affects stability by changing where the buoyant force acts along the ship’s length. When the vessel trims, the fore-aft difference in submerged depth (the forward-aft draft difference, CT) changes, which shifts the center of buoyancy relative to the center of gravity. That shift alters the metacentric height (GM) and, consequently, the righting lever that resists heeling.

In other words, stability responds directly to how much more water is under the bow versus the stern. The other factors—total weight, hull length, or overall water displacement—don’t change in the same immediate way with trim. Trim reorganizes the submerged volume, and CT is the direct measure of that change.