152. On a vessel of 15,000 tons displacement, compute the reduction in metacentric height due to free surface in a hold having free water in the tank tops. The hold is 50 feet long and 60 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 free surface (LB3/12) and ∇ is the displacement volume (Δ x 35 ft3/ton). With L = 50 ft, B = 60 ft, and Δ = 15,000 tons, this yields a reduction of 1.71 feet.