Waste disposal at sea

There are regulations governing what can and what can't be disposed of from ships or other structures in the sea. This is to prevent marine pollution, in particular with plastic in the sea contributing to the ocean garbage patch.

What you must do

You must have a licence before you can deposit substances or articles in the sea:

In Northern Ireland, you will need a marine licence.
In Scotland, contact Marine Scotland.

You can deposit some things without a licence, including:

whole or parts of fish or shellfish caught during certain licensed fishing operations, or processing at sea, as specified in regulations made under the Food and Environment Protection Act 1985
sewage originating on the vessel
food or domestic waste produced on the vessel
cooling or ballast water or tank washings
fishing gear (fixed and unfixed) other than for disposal.

For more information contact your relevant regulator:

DAERA: Marine Strategy and Licensing Branch

Marine Scotland

If you have a larger fishing vessel (over 400 gross tonnage (gt)) which you use for international voyages, you must meet additional requirements for sewage discharge. For more information, contact the Maritime and Coastguard Agency (MCA).

Maritime and Coastguard Agency

Disposal of oil at sea

You must not discharge any oil or any mixture with an oil content of more than 15 parts per million into the sea if your vessel:

is less than 12 miles from the nearest land
is stationary
does not have an oil-water separator
is within a special area (protected areas include the Mediterranean Sea, the Baltic Sea and the Antarctic).

Your anti-fouling system must meet certain legal requirements depending on the size of your vessel. It should meet the relevant requirements of the EU regulation on the prohibition of organotin compounds on ships, and the related International Maritime Organisation (IMO) convention. For more information, contact the MCA.

Maritime and Coastguard Agency

Good Practice

Do not dispose of non-degradable litter over the side of your boat – dispose of it appropriately when you return to shore.
Use a low-sulphur fuel to power your vessel if possible, to reduce the impact of fuel burning on the environment.
Carry out routine maintenance on your vessel to ensure that it uses fuel and oil as efficiently as possible, and to reduce the likelihood of spills or leaks while at sea.
If you have refrigeration on your vessel choose non-CFC based refrigerants wherever possible. CFCs are a major contributor to climate change.