The US Coast Guard issued a policy letter on 20 January 2006 advising its port state control officers about how they should conduct port state control examinations to enforce MARPOL Annex I. The emphasis is on the oily water separator (OWS), the oil content monitor (OCM), and the oil record book (ORB).
The letter provides details on what to look for and how to conduct various tests. We strongly advise that this document be required reading for chief engineers, masters, and shore side personnel, in particular technical management. We also recommend that your vessels follow the same inspection procedures on a regular basis. By doing so, there is a greater likelihood that your vessels will pass a port state control examination either by the US Coast Guard or another port state administration.