Maritime Law and International Conventions
This paper tests the legal framework in which the master operates: UNCLOS maritime zones, SOLAS and MARPOL obligations, STCW and MLC 2006, certificates and surveys, salvage and pollution liability, and port state control.
UNCLOS zones
- Internal waters: full sovereignty.
- Territorial sea: 12 nm from baselines, with the right of innocent passage.
- Contiguous zone: 24 nm, for customs, fiscal, immigration and sanitary enforcement.
- Exclusive economic zone: 200 nm, sovereign rights over resources.
- Archipelagic waters, straits used for international navigation, and the high seas complete the picture.
Pollution and liability (MARPOL)
Annex I oil, II noxious liquid substances, III harmful packaged substances, IV sewage, V garbage, VI air pollution. Under Annex I, discharges from machinery spaces must pass approved oily-water separating equipment at no more than 15 ppm. Cargo-area discharges from tankers need the ship en route, more than 50 nm from land, an instantaneous rate of no more than 30 litres per nautical mile, and a total limited to 1/30,000 (existing ships) or 1/15,000 (new ships) of the previous voyage's quantity. Liability regimes include CLC, Bunkers Convention, Nairobi Wreck Removal and LLMC.
Certificates and enforcement
The International Safety Management Certificate, Document of Compliance, Safety Construction and Equipment Certificates, International Oil Pollution Prevention Certificate, Load Line Certificate and ISSC all depend on valid surveys. Port state control can detain for deficiencies; the master's duty is to record protest, notify the flag state and owner, and not sign documents under duress.
Worked example
A tanker's previous voyage carried 240,000 t of oil. For an existing ship, the maximum total cargo-area discharge is 240,000 ÷ 30,000 = 8 t. A plan to discharge 12 t breaches Annex I even if the 30 L/nm rate and 50 nm distance are met.
Traps
- Confusing the contiguous zone (24 nm) with the EEZ (200 nm).
- Quoting the 15 ppm limit for cargo-area tanker discharges, which is a machinery-space limit.
- Assuming a certificate remains valid after an unreported damage or modification.