Your vessel displaces 840 tons and measures 146'L x 38'B. You ship a large wave on the after deck. What is the reduction in GM due to free surface before the water drains overboard, if the after deck measures 65'L x 38'B and the weight of the water is 76 tons?

Question

Accepted Answer

Option D: 9.27 feet. Solid masses of water trapped on deck create massive free surface effects due to the broad expanse of the deck area. For an 840-ton displacement vessel, a 65' by 38' deck pool of 76 tons causes a 9.27 feet GM reduction.