Candidates typically know the headline rules but fail at the practical, documentary layer — they cannot state which records are kept, for how long, who signs them, which certificates are carried, or what the Master's personal obligations are when a discharge occurs or is alleged. Examiners push here because it is where real command accountability lies.
The documentary framework a Master must own
Annex I — Oil:
- Oil Record Book Part I (machinery spaces) carried on vessels ≥400 GT; entries signed by the responsible officer, each completed page countersigned by the Master; retained on board for 3 years after the last entry.
- IOPP Certificate carried on vessels ≥400 GT operating internationally; 5-year cycle with intermediate surveys.
- Any overboard discharge must meet the ≤15 ppm standard via approved filtering equipment; the ship must be en route; equipment must not be inhibited. Vessels <400 GT retain oily residues on board for port reception.
- Antarctic waters: total prohibition on any operational discharge.
Annex VI — Air Emissions:
- Bunker Delivery Note (BDN) retained for 3 years after delivery (Reg 18.6).
- The MARPOL representative sample must be retained until the fuel is substantially consumed, and in any case for a minimum of 12 months (Reg 18.8.1).
- Sulphur limits: 0.50% globally (in force since 2020); 0.10% in SOx Emission Control Areas. The Mediterranean became a SOx ECA on 1 May 2025.
Annex V — Garbage:
- Garbage Management Plan (GMP) required on vessels ≥100 GT or certified to carry 15 or more persons.
- Garbage Record Book required on the same threshold (changed from 400 GT to 100 GT on 1 May 2024).
- The Mediterranean Sea and Red Sea are Special Areas under Annex V; the Red Sea Special Area provisions entered into force 1 January 2025.
What examiners probe at command level
A Master is responsible for ensuring entries are made in real time and are accurate — not just countersigning at the end of a voyage. If port State control finds a missing or inconsistent ORB entry, the Master is personally exposed. Know that falsifying an ORB entry is a criminal offence under UK law.
For bunkering, the Master must ensure the correct grade of fuel is loaded, the BDN is checked and retained, the representative sample is sealed and labelled with the ship's name, port, date, and fuel grade, and stored securely. This is not a chief engineer task the Master can delegate and ignore.
When asked about Special Areas, be specific: state which annex each area falls under. The Mediterranean is a Special Area under both Annex I and Annex V — not Annex IV. Confusing this is a common error.