What is LCF?

• A. The axis about which a ship inclines through the geometric center of the waterline
• B. The longitudinal centerline of the hull
• C. The distance from the waterline to the center of gravity
• D. The maximum load factor of the ship

Answer: (A)

LCF stands for Longitudinal Center of Flotation. It identifies the longitudinal location along the hull where the buoyant force effectively acts, which defines the axis about which the ship tends to rotate when weight distribution changes (trim/heel) in the longitudinal direction. Conceptually, this axis runs lengthwise through the geometric center of the waterline, making it the best descriptor among the options. The hull’s fixed centerline is just a reference line and does not describe where buoyancy acts; the vertical distance from the waterline to the center of gravity relates to stability in a different sense (vertical balance), not the buoyant pivot; and the maximum load factor is not a naval-architecture buoyancy concept.