A 7,000 ton displacement tankship carries two slack tanks of alcohol with a S.G. of 0.8. Each tank is 50 ft. long and 30 ft. wide. What is the reduction in GM due to free surface with the vessel floating in sea water, S.G. is 1.026?

Correct Answer: Option C — .72 ft

Multiple slack tanks require summing individual free surface moments. For two tanks (50'x30'), specific gravity 0.8, and 7,000 tons displacement in saltwater (1.026), the total reduction in metacentric height is calculated as 0.72 feet using standard stability principles.