160. On a vessel of 10,000 tons displacement, compute the reduction in metacentric height due to free surface in a hold having free water on tank tops. The hold is 50 feet long and 50 feet wide. What is the reduction in metacentric height?

The reduction in metacentric height due to free surface is calculated using the formula FSC = I/∇, where I is the second moment of area of the water surface and ∇ is the vessel's displacement volume. For a rectangular hold, I = (b3·l)/12. With a displacement of 10,000 tons and dimensions of 50 feet by 50 feet, the calculation yields a reduction of approximately 1.5 feet.