Which term describes stability along the length of the boat?

• A. Longitudinal stability
• B. Transverse stability
• C. Vertical stability
• D. Lateral stability

Answer: (A)

Longitudinal stability describes how the boat behaves in the fore‑aft direction—from bow to stern. It’s about resisting tilting or pitching along the length when forces act along that axis, such as weight shifting toward the bow or stern or waves pushing on the bow. A vessel with good longitudinal stability tends to return toward a level trim after fore‑aft disturbances, thanks to how buoyancy and the weight distribution along the hull interact in the longitudinal plane.

This is distinct from stability side‑to‑side, which is about rolling and is referred to as transverse or lateral stability. Vertical stability, while a related concept, concerns motions in the up‑down direction and isn’t what’s meant by stability along the length. So the term that matches “stability along the length” is longitudinal stability.