Lesson M500-3.1.4: The Master's Pollution Duties, Obligations, Liabilities and Records
You are the Master of a 380 GT superyacht transiting the western Mediterranean at night. Your chief engineer calls at 0230: a hydraulic line has fractured near the bilge; oily water has entered the bilge space and the bilge pump has activated automatically. He asks whether he can discharge. This is your decision — not his.
The Master's Personal Responsibility
MARPOL imposes obligations on the ship — but in any prosecution, the Master is the individual who carries criminal liability for unlawful discharge. In the UK, the Merchant Shipping Act 1995 and associated regulations make the Master (and potentially the owner) liable for discharges in UK waters. The Flag State may pursue the same route internationally. 'I didn't know' is not a defence if you had means to know.
Your first duty in the vignette above is therefore to stop the discharge and assess the situation before any decision to pump.
Key Discharge Rules (Annex I — Oil)
Your vessel is 380 GT. The critical thresholds:
- Filtering equipment and the 15 ppm discharge standard apply to ships ≥400 GT. Your vessel is below that threshold.
- Ships <400 GT are required to retain oily residues on board for discharge to port reception facilities — there is no permitted overboard discharge of oily bilge water unless specific coastal-state rules allow it (MARPOL Annex I Reg 15.6).
- The Mediterranean is a Special Area under Annex I: even if your vessel were ≥400 GT, the more restrictive Special Area standards would apply. No operational discharge of oil is permitted in Special Area waters.
- The Antarctic imposes a total prohibition on any oil discharge.
In your vignette: the answer to the chief engineer is no discharge. Retain in the bilge or transfer to a holding tank; engage port reception when you arrive.
Records the Master Is Responsible For
Oil Record Book (ORB) Part I is mandatory for machinery space operations. For yachts, this applies from ≥400 GT. Your 380 GT vessel is not required to carry an ORB Part I — however, any Flag State or coastal State can demand evidence of what occurred. A contemporaneous written record in the Deck Log is your protection.
Where an ORB is carried:
- Entries signed by the responsible officer; each page countersigned by the Master.
- Retained for 3 years after the last entry.
- Available for inspection by Port State Control at any time.
IOPP Certificate: required for vessels ≥400 GT trading internationally; 5-year survey cycle.
Reporting Obligations
If a discharge occurs — whether accidental or suspected — the Master has a duty to report. Under MARPOL Article 8 and Protocol I, the Master must report without delay to the nearest coastal State when a discharge occurs or is likely. Failure to report is itself an offence, separate from the discharge.
Report contains: ship identity, position, date/time, nature of discharge, quantity if known, cause, and action taken. The report goes to the coastal State authority (in UK waters: MCA via the relevant MRCC).
Liabilities in Practice
- Criminal prosecution of the Master personally (in the Flag State and/or coastal State).
- Port State Control detention — a vessel will not sail if PSC considers it a pollution risk.
- P&I Club cover may be jeopardised by deliberate discharge.
- The Master's Certificate is at risk — MCA may suspend or cancel it following conviction.
The command standard here is simple: when in doubt, retain, record, and report.