[Governor Dinwiddie]

I understand that the New Madrid Earthquake of 1811 caused the ground to "liquify" and many structures sank into it. This effect with the ships sounds similar.
 

[DUMBGRUNT]

Not my line of work, but with the earthquake, the soil behaves LIKE a fluid.

Under some conditions, the balk cargo (dry powder) in the hold of a ship BECOMES a liquid.