Marine Pollution Prevention and Environmental Protection
Core concepts
Know MARPOL Annexes I to VI: oil, noxious liquid substances, harmful substances in packaged form, sewage, garbage, and air pollution. Understand the Oil Record Book, garbage record book, and the 15 ppm bilge alarm and oily water separator requirements. Learn about sulphur limits, nitrogen oxide controls, and the prohibition on deliberate discharge.
Traps in questions
- Assuming oily water can be discharged anywhere below 15 ppm; special areas and distance limits apply.
- Forgetting that the Oil Record Book entries must be signed and retained.
- Mixing up Annex IV (sewage) with Annex V (garbage).
- Overlooking that plastics may never be discharged, even outside special areas.
Rule of thumb and worked example
Bilge water generation: if a vessel produces 0.5 m³ of bilge per day and the separator processes 1 m³/h, running for 30 minutes daily is sufficient, but the 15 ppm alarm must be tested and the overboard valve sealed when in port. Rule of thumb: any discharge must satisfy three tests-permitted substance, permitted location, and permitted rate or concentration. If any one fails, retain on board.
Study focus
Revise the contents and retention periods of the Oil Record Book and garbage record book, and the meaning of special areas. Understand the purpose of the sewage treatment plant and the difference between comminuted and treated discharge. Know the shipboard emergency plan for oil spills (SOPEP) and the role of the engineer in pollution response.