When buoyancy moves up, where does the metacenter move?

When buoyancy moves up, where does the metacenter move?

• A. Down
• B. Up
• C. Left
• D. Right

Answer: (A)

The metacenter is determined by how the buoyancy force shifts as the hull heels. For small tilts, it’s the intersection of the buoyancy force line (which changes with the center of buoyancy) with the hull’s vertical through the centerline. If the center of buoyancy moves upward within the hull as the ship tilts, that shift makes the intersection point occur lower relative to the hull, so the metacenter moves downward. This downward movement of the metacenter, with the center of gravity fixed, reduces the metacentric height and can decrease stability.

The metacenter is determined by how the buoyancy force shifts as the hull heels. For small tilts, it’s the intersection of the buoyancy force line (which changes with the center of buoyancy) with the hull’s vertical through the centerline. If the center of buoyancy moves upward within the hull as the ship tilts, that shift makes the intersection point occur lower relative to the hull, so the metacenter moves downward.

This downward movement of the metacenter, with the center of gravity fixed, reduces the metacentric height and can decrease stability.