57. The liquid mud tanks on your vessel measure 30'L by 15'B by 6'D. The vessel's displacement is 968 T 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 mud tanks is calculated by determining the free-surface moment of each tank, converting the specific gravity to weight density, and dividing by the vessel's displacement; the total reduction is approximately 0.87 feet.