Question 4590 Deck General

The correct answer is D) at all times. For a floating MODU (Mobile Offshore Drilling Unit), the center of buoyancy and the metacenter are always in the line of action of the buoyant force, regardless of the stability condition (positive, negative, or neutral). This is because the buoyant force, which acts vertically upward through the center of buoyancy, must pass through the metacenter to maintain equilibrium and stability. The metacenter is the point where the buoyant force intersects the vessel's centerline, and it is this relationship that must be maintained at all times for the MODU to remain stable. The other options are incorrect because the relationship between the center of buoyancy, metacenter, and the buoyant force is not dependent on the specific stability condition of the MODU.