The SS AMERICAN MARINER is ready to bunker with drafts of FWD 11'-01", AFT 15'-01". After all bunkers are on board, soundings indicate the tonnages shown in table ST-0086 below. Use the white pages of The Stability Data Reference Book to determine the free surface correction.

Correct Answer: Option A — 0.68 foot

The free surface effect is independent of the vessel's heel but directly proportional to the tank's breadth cubed. Using the ST-0086 table data and the vessel's displacement at the given draft, the calculated free surface correction for the slack tanks is 0.68 feet.