What is MARPOL? Understanding Marine Pollution Rules for Yachts and Ships

MARPOL is short for “Marine Pollution”, and refers to the International Convention for the Prevention of Pollution from Ships. It’s a global agreement developed by the International Maritime Organization (IMO) to prevent pollution from ships — both accidental and operational.

The full name is: MARPOL 73/78, referring to the years of its adoption and updates.

What Does MARPOL Cover?

MARPOL is divided into six key sections, called Annexes, each dealing with a different type of pollution:

• Annex I – Oil pollution (e.g. fuel leaks, bilge water)

• Annex II – Chemicals carried in bulk

• Annex III – Packaged harmful substances

• Annex IV – Sewage and blackwater

• Annex V – Garbage and plastics

• Annex VI – Air pollution (sulphur emissions, exhaust gases)

Does MARPOL Apply to Yachts?

Yes — depending on your yacht’s size, usage, and flag state. MARPOL regulations are especially relevant if your vessel:

• Is over 400 gross tons

• Travels internationally

• Operates as a commercial or charter yacht

• Discharges sewage, bilge, or garbage

• Uses fuel with sulfur content

Even private yachts are encouraged to follow MARPOL best practices, especially in environmentally sensitive waters.

Examples of MARPOL in Action

• Using holding tanks for blackwater until legal discharge zones

• Separating plastics, food waste, and general garbage

• Keeping oil record books up to date

• Burning low-sulphur fuel in Emission Control Areas (ECAs)

• Installing sewage treatment systems that meet Annex IV standards

Why It Matters

MARPOL isn’t just a rulebook — it’s about real-world impact. From microplastics and oil slicks to air quality in port cities, MARPOL helps:

• Protect marine life

• Keep coastal waters clean

• Ensure your yacht remains compliant when entering international ports

• Improve crew safety and environmental awareness

Failure to follow MARPOL can lead to heavy fines, detention, or damage to a yacht’s reputation.

MARPOL is the world’s main framework for preventing marine pollution from ships and yachts. Whether you’re a private owner or managing a commercial vessel, understanding MARPOL helps you operate responsibly — and legally — at sea.

FAQs About MARPOL (Marine Pollution Convention)

What does MARPOL stand for?

MARPOL stands for Marine Pollution and refers to the International Convention for the Prevention of Pollution from Ships. It’s the main global agreement aimed at reducing pollution caused by vessels at sea.

Does MARPOL apply to yachts?

Yes, depending on the size, flag, and usage of the yacht:

• Commercial and charter yachts must follow MARPOL rules strictly

• Private yachts under 400 GT may be exempt from some rules, but are encouraged to comply

• All yachts are expected to avoid polluting the sea with oil, sewage, garbage, or exhaust emissions

What are the MARPOL Annexes?

MARPOL is divided into six main sections:

1. Annex I – Oil pollution

2. Annex II – Chemicals (bulk cargo)

3. Annex III – Packaged dangerous goods

4. Annex IV – Sewage (blackwater)

5. Annex V – Garbage (including plastics)

6. Annex VI – Air pollution (sulphur, NOx emissions)

For most yachts, Annexes I, IV, V, and VI are the most relevant.

What is an Oil Record Book?

An Oil Record Book is a log where crew record any discharge or handling of oily waste — such as bilge water, sludge, or fuel spills. It’s required on most vessels over 400 GT and must be available for inspection.

Can we discharge sewage at sea?

Yes — but only under strict conditions. According to MARPOL Annex IV:

• You must be a certain distance from land (usually >12 nautical miles)

• You must use a certified sewage treatment system

• In Special Areas, discharge is either restricted or completely prohibited

Is plastic allowed to be thrown overboard?

No. Under MARPOL Annex V, all plastic waste must be retained onboard and properly disposed of ashore. This includes packaging, bags, fishing gear, and synthetic lines. Dumping plastics at sea is illegal and environmentally harmful.

What are Emission Control Areas (ECAs)?

ECAs are special maritime zones where stricter controls apply to air pollution from ships. Yachts operating in these zones (e.g. North Sea, Baltic Sea, North America) must use low-sulphur fuel or have exhaust treatment systems in place.

What happens if we break a MARPOL rule?

Penalties can include:

• Fines or detention by port state authorities

• Problems with charter certification or insurance coverage

• Environmental damage and reputational risk

Even accidental pollution incidents must be reported properly to avoid more serious consequences.

How can we stay compliant?

• Use certified equipment (e.g. sewage systems, bilge separators)

• Train crew on MARPOL basics

• Keep required logbooks and certificates up to date

• Avoid discharging waste unless legally permitted

• Partner with shipyards and refit teams familiar with MARPOL standards