Condensation damage (ship's sweat and cargo sweat)

A load of coffee in bags leaves Santos, Brazil, in the middle of the austral summer, for Hamburg, crossing the equator and then the North Atlantic in autumn. The coffee, loaded warm and humid, gives off vapor in holds that cool gradually with latitude. When warm, humid air touches a surface below its dew point, water is deposited. Two situations are distinguished. Ship's sweat is condensation on the ship's cold structure, dripping onto the cargo: it occurs when a ship moves from a warm climate to a cold one, with warm, humid cargo and cold steel. Cargo sweat is condensation on the cold cargo when warm, humid air reaches it, through ventilation among other ways: it occurs when going from a cold climate to a warm one. The dew point rule draws the line: ventilate when the outside air is drier than the hold air, and when its dew point stays below the cargo's temperature; otherwise refrain. Damage ranges from mold on coffee or cocoa to rust on steel coils. In law, the question is whether the carrier ventilated properly, or whether the goods carried within them the moisture that ruins them, that is, an inherent vice excluded from insurance. All-risks cargo clauses cover condensation if it is fortuitous; they exclude it if it comes from inherent vice or insufficient packing.