What is CT?

• A. The change in difference between the forward and aft draft
• B. The vertical clearance between deck and waterline
• C. The center of thrust
• D. The coefficient of trim

Answer: (A)

CT stands for the change in trim—the amount by which the difference between the forward draft and the aft draft changes. Trim is the relative depth of the bow and stern in the water, so CT measures how that bow–stern difference varies as weight distribution or buoyancy changes (like adding ballast, flooding a compartment, or shifting loads). For example, moving ballast forward or increasing fuel toward the bow will increase the forward draft relative to the aft draft, changing the trim in that direction. The other concepts describe things like vertical clearance (freeboard), the center of thrust, or a trim coefficient, none of which reflect how the forward–aft draft difference itself changes.