120. A few hours after changing the oil on one of the diesel generator set engines on your offshore supply vessel, you notice that the oil is significantly darkened. What does this normally indicate?

Darkening of lubricating oil shortly after an oil change typically indicates the suspension of unburned carbon (soot), a normal occurrence due to combustion and detergent additives in the oil, and does not necessitate another oil change unless other abnormal indications are present.