Your vessel displaces 747 tons and measures 136'L by 34'B. You ship a large wave on the after deck. What is the reduction to GM due to free surface before the water drains overboard, if the after deck measures 56'L x 34'B and the weight of the water is 58.6 tons?

Correct Answer: Option C — 6.51 feet

Water shipped on deck acts as a free surface, drastically decreasing vessel stability. The effective reduction in GM is computed using FSC = (i / V) adjusted for the shipped water's mass and dimensions, resulting in a severe 6.51 feet loss.