58. The liquid mud tanks on your vessel measure 32'L by 15'B by 8'D. The vessel's displacement is 640 tons and the specific gravity of the mud is 1.8. What is the reduction in GM due to a pair of these tanks (p/s) being slack?

The reduction in GM due to two slack tanks is calculated by determining the total free-surface moment (specific gravity times the sum of the second moments of area of the tanks) and dividing it by the vessel's displacement volume, resulting in a reduction of approximately 1.41 feet.