On a vessel of 6,000 tons displacement there are two slack tanks of carbon tetrachloride (SG 1.6). Each tank is 40 feet long and 25 feet wide. What is the reduction in metacentric height due to free surface with the vessel in sea water (SG 1.025)?

Correct Answer: Option B — .77 ft

High-density liquids increase free surface penalties proportionally. For two tanks (40'x25') holding carbon tetrachloride (SG 1.6) on a 6,000-ton vessel floating in seawater (SG 1.025), the combined free surface reduction in metacentric height equals 0.77 feet.