What are the reference points for keel, center of gravity, center of buoyancy, and metacenter?

What are the reference points for keel, center of gravity, center of buoyancy, and metacenter?

• A. (M) (G) (B) (K)
• B. (K) (B) (G) (M)
• C. (G) (M) (K) (B)
• D. (B) (K) (M) (G)

Answer: (A)

Think about how these reference points sit along the ship’s vertical axis when the hull is upright. The metacenter sits highest, because it’s the point related to the restoring tendency when the ship heels. The center of gravity lies below it, since it’s the overall weight’s location. The center of buoyancy tends to be below the CG as the hull shape causes the buoyant force to shift with displacement. The keel is the lowest point on the hull. Reading top to bottom, the order is metacenter, center of gravity, center of buoyancy, keel. This is why the arrangement listing M, then G, then B, then K is the best match.

Think about how these reference points sit along the ship’s vertical axis when the hull is upright. The metacenter sits highest, because it’s the point related to the restoring tendency when the ship heels. The center of gravity lies below it, since it’s the overall weight’s location. The center of buoyancy tends to be below the CG as the hull shape causes the buoyant force to shift with displacement. The keel is the lowest point on the hull. Reading top to bottom, the order is metacenter, center of gravity, center of buoyancy, keel. This is why the arrangement listing M, then G, then B, then K is the best match.