Diving was done daily in order to adjust the trim of the boat and to determine the salinity of the water at different depths. A war time dive could be completed in 30 seconds. A submarine going into a dive causes a shifting of the center of gravity and the center of buoyancy. The metacenter is a point where the center of gravity of the boat coincides with the center of buoyancy; a very hazardous point which must be passed quickly. If the center of gravity and the center of buoyancy are coincident and if a wave were to hit the boat from the side, capsizing could occur.
Jack Higgins and Paul Wittmer
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