The SS AMERICAN MARINER is ready to bunker with drafts of FWD 17'-06", AFT 20'-04". After all bunkers are on board, soundings indicate the tonnages shown in table ST-0178 below. Use the white pages of The Stability Data Reference Book to determine the free surface correction.

Correct Answer: Option D — 1.31 feet

The virtual loss of GM due to slack tanks is determined by the formula FSC = FSM / Displacement. Utilizing the data from table ST-0178 for the SS AMERICAN MARINER, the sum of the free surface moments divided by the vessel's displacement at the given draft yields 1.31 feet.