Marine licensing exempted activities
Source: gov.uk (2025-11-18)

This guidance explains which activities may be exempt from needing a marine licence, the conditions that apply, and how to notify the Marine Management Organisation (MMO).

Overview

Some activities at sea are exempt from needing a marine licence. Exemptions are set out in the Marine and Coastal Access Act 2009 under Marine Licensing (Exempted Activities) Orders 2011, 2013 and 2019.

If you want to rely on an exemption, you must:
- meet all the qualifying criteria and conditions
- notify the MMO if required
- get any other consents needed for your activity
You can check if your activity is exempt before you apply (https://marinelicensing.marinemanagement.org.uk/mmofox5/journey/self-service/start).

Enforcement action may be taken if you carry out an activity without a marine licence and it does not qualify as exempt.

Getting consent from a harbour or lighthouse authority

Some exemptions only apply if you have consent from a harbour or lighthouse authority.

This means formal permission granted under that authority’s local or statutory powers, not just general agreement.

If you need consent, contact the relevant authority directly. They will tell you:

how to apply for consent

what information they need

any local requirements or conditions that may apply

You must have this consent before you start an activity that relies on the exemption.

Definitions

Harbour authority means any person or organisation with powers or duties to improve, maintain or manage a harbour. This definition is set out in section 57(1) of the Harbours Act 1964.

Lighthouse authority means a general or local lighthouse authority within the meaning of Part 8 of the Merchant Shipping Act 1995.

Markers, moorings and pontoons

Moorings and aids to navigation

You do not need a licence to deposit, construct or remove moorings or aids to navigation if the work is carried out by a harbour or lighthouse authority.

If you’re not one of these authorities, you can still use the exemption if you have their consent. In that case, you must notify the MMO before you start.

What you need to do
- harbour or lighthouse authority – no action required
- everyone else – get consent from the relevant authority and notify the MMO
Read the full legislation in Article 25 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/25), 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/11) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/10/made).

Temporary markers

You do not need a marine licence to place a marker if it is either:
- removed within 24 hours
- removed within 28 days and you notify the MMO before you start
The exemption does not apply if the activity is likely to:
- cause damage to features of archaeological or historic interest
- significantly affect a marine protected area
See ‘Common exemption conditions’ for more about marine protected areas and archaeological features.

What you need to do
- if removing markers within 24 hours – no action required
- if leaving in place up to 28 days – notify the MMO
Read the full legislation in Article 26A of the Exempted Activities Order 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/13) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/11/made).

Pontoons

You do not need a marine licence to construct, deposit or remove a pontoon of 30 square metres or less if the work is carried out by a harbour authority.

If you are not a harbour authority, you can still use the exemption with their consent, but you must notify the MMO before you start.

The MMO must approve the activity if more than 10 pontoons have been constructed or deposited by the harbour authority (or with its consent) in the previous 6 months.

What you need to do
- harbour authority – no action required unless more than 10 pontoons have been constructed or deposited in 6 months. In that case, get MMO approval
- everyone else – get consent from the harbour authority and notify the MMO
Read the full legislation in Article 25A of the Exempted Activities Order 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/12).

Markers for European marine sites and marine conservation zones

You do not need a marine licence if:
- Natural England places or removes boundary markers for European marine sites
- a public authority places or removes boundary markers for Marine Conservation Zones
What you need to do

Natural England or public authority – notify the MMO before you place or remove markers.

Read the full legislation in Article 26 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/26).

Diver trails within restricted areas

You do not need a marine licence to place or remove signage or markers for diver trails on:
- wrecks protected under the Protection of Wrecks Act 1973 (http://www.legislation.gov.uk/ukpga/1973/33)
- scheduled monuments under the Ancient Monuments and Archaeological Areas Act 1979 (https://www.legislation.gov.uk/ukpga/1979/46/section/1)
- controlled sites under the Protection of Military Remains Act 1986 (https://www.legislation.gov.uk/ukpga/1986/35/section/1)
You must still get consent under those acts.

What you need to do

Get consent from the relevant authority. This will usually come from Historic England for protected wrecks or scheduled monuments, or the Ministry of Defence for military sites.

Read the full legislation in Article 31 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/31) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/13/made).

Litter

Recovery of marine litter during diving

You do not need a marine licence to remove marine litter, including abandoned fishing gear, during a dive.

The exemption does not apply if the activity is likely to:
- cause damage to features of archaeological or historic interest
- significantly affect a marine protected area
See ‘Common exemption conditions’ for more about marine protected areas and archaeological features.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 21A of the Exempted Activities Order 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/8/made).

Use of vehicles or vessels by harbour authorities to remove marine litter and debris

Harbour authorities do not need a marine licence to remove litter or debris using vehicles or vessels.

The exemption does not apply if the activity is likely to:
- cause damage to features of archaeological or historic interest
- significantly affect a marine protected area
See ‘Common exemption conditions’ for more about marine protected areas and archaeological features.

What you need to do

No action required if you are a harbour authority.

Read the full legislation in Article 24A of the Exempted Activities Order 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/9/made).

Use of vehicles to remove litter, seaweed or dead animals

You do not need a marine licence to remove litter, seaweed or dead animals from a beach or intertidal area if the work is carried out by, or on behalf of, a local authority.

This exemption does not apply if the activity is likely to have a significant effect on a marine protected area.

See ‘Common exemption conditions’ for more about marine protected areas.

What you need to do
- removing litter or seaweed – no action required
- removing dead animals – notify the MMO
Read the full legislation in Article 21 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/21), 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/9) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/7/made)

Scientific research

Scientific instruments

You do not need a marine licence to deposit or remove scientific instruments or associated equipment, if the purpose is a scientific experiment or survey.

The exemption does not apply if the deposit:
- is tethered to the seabed
- reduces navigational clearance by more than 5% of chart datum
- is likely to cause obstruction or danger to navigation
- is likely to significantly affect a marine protected area
- is made for disposal
See ‘Common exemption conditions’ for more about marine protected areas and navigational risk.

What you need to do

Notify the MMO before you start.

Read the full legislation in Article 17 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/17) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/4/made).

Tracers and reagents

You do not need a marine licence to deposit tracers or reagent approved for use by the MMO, if you follow the conditions of approval.

What you need to do
- check the MMO approved list (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/493960/Approved_list_of_tracers__conditions_and_best_practice.pdf)
- notify the MMO before you start
Read the full legislation in Article 17 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/17).

Samples for testing and analysis

You do not need a marine licence to remove of up to 1 cubic metre of material for testing or analysis.

This exemption does not apply if the activity is likely to:
- cause an obstruction or danger to navigation
- significantly affect a marine protected area
See ‘Common exemption conditions’ for more about marine protected areas and navigational risk.

What you need to do

Notify the MMO before you start.

Read the full legislation in Article 17A of the Exempted Activities Order 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/7).

Maintenance

Harbour works

You do not need a marine licence for works by or on behalf of a harbour authority to maintain harbour works.

The exemption does not apply if work is outside the existing boundaries.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 23 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/23).

Coastal protection, drainage and flood defence

You do not need a marine licence for works to maintain coast protection, drainage or flood defences by, or on behalf of:
- the Environment Agency
- a local authority
- a coast protection authority
- the Secretary of State for Defence
The exemption includes beach reprofiling and recycling, but not replenishment, or any activity carried out outside the existing boundaries.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 19 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/19) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/5/made).

Dredging

Harbour authorities

You do not need a marine licence for dredging or depositing dredged material if both of the following apply:
- the activity is authorised under a Harbour Order or local act
- it is carried out by or on behalf of a harbour authority
For disposal of dredged material, the exemption only applies if the following additional conditions are also met:
- the activity relocates sediments within surface waters
- the purpose is to manage waters or waterways, prevent floods, mitigate the effects of floods or droughts, or land reclamation
- the MMO is satisfied the sediments are not hazardous waste
What you need to do

If disposal is involved, you must provide evidence to the MMO that the sediments are not hazardous waste.

Read the full legislation in Section 75 of the Marine and Coastal Access Act 2009 (http://www.legislation.gov.uk/ukpga/2009/23/section/75).

Low volume navigational dredging

You do not need a marine licence for low volume dredging to maintain navigation.

The exemption does not apply if:
- there is no history of dredging at the site in the last 10 years
- the dredged volume exceeds 500 cubic metres in one activity
- the dredged volume combined with any dredging in the past 12 months exceeds 1,500 cubic metres
- the activity is likely to cause an obstruction or danger to navigation
- the activity is likely to significantly affect a marine protected area
- the activity is likely to affect the status of the waterbody
See ‘Common exemption conditions’ for more about navigational risk, marine protected areas and waterbody status.

This exemption does not allow disposal of dredged material at sea.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 18A of the Exempted Activities Order 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/8).

Deposits during aggregate or mineral dredging

You do not need a marine licence to return any substance or object to the sea, taken at the dredge site during aggregate or mineral dredging.

This exemption covers:
- objects such as old munitions, litter or other items brought up during dredging
- water discharged from the hold either during the operation, on completion, or on the return trip to port
It does not apply to the aggregates or minerals being dredged. Where safe to do so, we encourage vessels to return litter to shore for recycling rather than discharge it at sea.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 18 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/18).

Fishing and Shellfish

Shellfish propagation and cultivation

You do not need a marine licence to deposit and remove shellfish or equipment used in shellfish farming, such as cages, ropes, poles or trestles.

The exemption does not apply if the activity:
- is for construction, artificial reefs or disposal
- is likely to cause an obstruction or danger to navigation
See ‘Common exemption conditions’ for more about navigational risk.

What you need to do

Notify the MMO before you start.

Read the full legislation in Article 13 of the Exempted Activities order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/13) and 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/4).

Fishing operations

You do not need a marine licence to:
- deposit or remove fishing gear
- catch or remove fish or shellfish
- return fish or removed objects to the sea
The exemption does not apply if deposits are made for disposal purposes.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 12 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/12).

Cables, pipelines, oil and gas and carbon storage

Cables for electricity or data

You do not a need a marine licence to lay or maintain an exempt cable outside English inshore waters.

An exempt cable is one used to transfer electricity or data from one place to another. It does not include cables used to export electricity from a renewable energy array to a substation on land.

If a cable crosses both English inshore and offshore waters:
- maintenance of the existing cable is exempt along its whole route
- laying a new cable requires a marine licence for the section within English inshore waters
If the cable runs through devolved inshore waters (Scotland, Wales or Northern Ireland), you will need consent from the relevant administration.

What you need to do
- if the work is maintenance, you can carry it out under this exemption
- if it involves laying a new cable within English inshore waters, use the Get permission for marine work (https://marinelicensing.marinemanagement.org.uk/mmofox5/journey/self-service/start) service to find out what licence you need
- if the cable runs through devolved inshore waters, contact the relevant administration
Read the full legislation in Section 81 of the Marine and Coastal Access Act 2009 (https://www.legislation.gov.uk/ukpga/2009/23/section/81)

Emergency cable inspection or repair

You do not need a marine licence for emergency inspection, cable inspections or repairs.

Emergency means a serious, unexpected, or dangerous situation requiring immediate action.

The exemption does not apply to cable protection, deposits or explosives.

What you need to do

Notify the MMO within 24 hours of starting.

Read the full legislation in Article 34 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/34) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/14/made).

Oil and gas and carbon capture and storage

You do not need a marine licence for activities covered by the Petroleum Act 1998, such as:
- petroleum exploration and extraction
- establishing or maintaining offshore energy installations
- energy pipelines and installations
- gas storage or recovery
- carbon dioxide storage
You do not need a marine licence for activities that require a permit under:
- the Offshore Chemicals Regulations 2002
- the Offshore Petroleum Activities Regulations 2005
This exemption does not apply to the construction, alteration or improvement of any other pipeline.

What you need to do

No action required if conditions are met.

Read the full legislation in Section 77 of the Marine and Coastal Access Act 2009 (https://www.legislation.gov.uk/ukpga/2009/23/section/77).

Emergency inspection or repair of a pipeline

You do not need a marine licence for emergency pipeline inspections or repairs.

Emergency means a serious, unexpected, or dangerous situation requiring immediate action.

This exemption does not apply to pipeline protection, deposits or explosives

What you need to do

Notify the MMO within 24 hours of starting.

Read the full legislation in Article 34 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/34) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/14/made).

Vessels

Launching vessels

You do not need a marine licence to launch a vehicle, vessel, aircraft, marine structure or floating container.

The exemption does not apply if the activity involves construction, dredging, removal or explosives.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 27 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/27).

Deposits during normal navigation

You do not need a marine licence for deposits made in the normal course of navigation or maintenance.

The exemption does not apply to disposal, hull cleaning or explosives.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 22 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/22).

Hull cleaning

You do not need a marine licence for in-water hull cleaning, provided if is done by hand using:
- a soft cloth
- a sponge
- a soft-bristled brush
- sandpaper with a grit size of P2000 or less
What you need to do

No action required if conditions are met.

Read the full legislation in Article 27A of the Exempted Activities Order 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/12/made).

Dismantling of ships

You do not need a marine licence for deposit or removal activities carried out as part of dismantling a ship that is waste.

The exemption does not apply to deposits made for disposal, explosives, construction, dredging or scuttling (sinking).

What you need to do

No action required if conditions are met.

Read the full legislation in Article 28 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/28).

Salvage

You do not need a marine licence for official salvage operations to ensure ship safety or prevent pollution.

The exemption does not apply to removal of wrecks or objects of archaeological or historic interest.

See ‘Common exemption conditions’ for more about archaeological or historic interest.

Read the full legislation in Article 9 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/9).

Rights of foreign vessels

You do not need a marine licence if activities are carried out by foreign vessels exercising rights under international law.

These rights apply to:
- vessels flying the flag of a non-UK, non-EU state
- state-owned vessels or aircraft used only for government non-commercial service
What you need to do

No action required if conditions are met.

Read the full legislation in Article 37 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/37).

Pollution response

Equipment to control oil or pollution

You do not need a marine licence to deposit equipment intended to control, contain or recover:
- oil
- mixtures containing oil
- chemicals
- flotsam
- algal blooms
The exemption does not apply to the deposit or use explosives.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 16 of the Exempted Activities Order 2016 (http://www.legislation.gov.uk/uksi/2011/409/article/16).

Marine chemical and oil treatment substances

You do not need a marine licence to use products approved by the MMO to:
- disperse or treat oil spills
- treat chemical pollution
- tackle fouling of the sea or seabed
What you need to do

Use the guidance on marine pollution incidents (https://www.gov.uk/guidance/how-we-respond-to-marine-pollution-incidents#report-and-respond-to-a-marine-pollution-incident) to get approval from MMO or report a marine pollution incident.

Read the full legislation in Article 15 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/15).

Activities covered by the Merchant Shipping Act 1995

You do not need a marine licence for activities covered by Part 6 of the Merchant Shipping Act 1995 (prevention of pollution).

This includes:
- deposit of oil or mixtures containing oil
- deposit or incineration of garbage from vessels
- deposit of cooling water or ballast water
What you need to do

No action required if conditions are met.

Read the full legislation in Article 7 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/7).

Emergency, safety and training

Emergency for flood risk

You do not need a marine licence for emergency works by or on behalf of the Environment Agency for floods or imminent flood risk.

Emergency means a serious, unexpected, or dangerous situation requiring immediate action.

What you need to do

Notify the MMO within 168 hours (7 days) of starting.

Read the full legislation in Article 20 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/20) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/6/made).

Emergency inspection or repair of cables or pipelines

You do not need a marine licence for emergency inspection or repair of a cable or pipeline.

Emergency means a serious, unexpected, or dangerous situation requiring immediate action.

The exemption does not apply to deposits of cable or pipeline protection material or explosives.

What you need to do

Notify the MMO within 24 hours of starting.

Read the full legislation in Article 34 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/34) and 2019 (http://www.legislation.gov.uk/uksi/2019/893/article/14/made).

Removing obstructions or danger to navigation

You do not need a marine licence to remove anything causing or likely to cause an obstruction or danger to navigation, if you are a:
- conservancy authority
- harbour authority
- lighthouse authority
- other navigation body
See ‘Common exemption conditions’ for more about navigational risk.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 24 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/24).

Accidental deposits

You do not need a marine licence to remove objects accidentally deposited on the seabed, such as anchors, rock or equipment.

The exemption does not apply if the removal:
- is more than 12 months after the deposit
- is likely to cause an obstruction or danger to navigation
- is likely to significantly affect a marine protected area
See ‘Common exemption conditions’ for more about marine protected areas and navigational risk.

What you need to do

Notify the MMO before you start.

Read the full legislation in Article 17B of the Exempted Activities Order 2013 (http://www.legislation.gov.uk/uksi/2013/526/article/7)

Coastguard activities

You do not need a marine licence for activities carried out by or on behalf of the Maritime and Coastguard Agency to:
- secure the safety of a vessel, aircraft or marine structure
- save life
- carry out training for these purposes
What you need to do

No action required if conditions are met.

Read the full legislation in Article 32 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/32).

Flares and pyrotechnics for safety and training

You do not need a marine licence to deposit and use smoke floats, distress flares or similar items to:
- secure the safety of a vessel, aircraft or marine structure
- save life
- carry out training for these purposes
What you need to do

No action required if conditions are met.

Read the full legislation in Article 33 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/33).

Safety directions under the Merchant Shipping Act 1995

You do not need a marine licence for any activity carried out under direction from the Secretary of State’s representative after an accident to or in a ship that risks safety or pollution.

The exemption only applies to:
- the owner, master, pilot or anyone else in control of the ship
- anyone acting on their behalf, such as an agent or contractor
What you need to do

No action required if conditions are met.

Read the full legislation in Article 8 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/8).

Fire fighting

You do not need a marine licence for activities to fight or prevent the spread fire.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 10 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/10).

Exemptions for other activities

Crossrail Act 2008

You do not need a marine licence for activities carried out under the Crossrail Act 2008 (http://www.legislation.gov.uk/ukpga/2008/18/contents) if they are:
- part of scheduled works listed in the act
- within the limits of deviation, which are the boundaries shown on the deposited plans
What you need to do

No action required if conditions are met.

Read the full legislation in Article 29 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/29).

Deep sea mining

You do not need a marine licence for activities regulated under the Deep Sea Mining (Temporary Provisions) Act 1981.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 30 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/30).

Bored tunnels

You do not need a marine licence for tunnel works carried out wholly under the seabed.

The exemption does not apply if the activity involves:
- depositing material for disposal
- works on the seabed or in the sea
- significant adverse impact on the UK marine area or the living resources it supports
What you need to do

Notify the MMO before you start.

Read the full legislation in Article 35 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/35).

Defence activities

You do not need a marine licence for activities carried out in defence of the realm by or on behalf of:
- the UK armed forces
- reserve forces
- the Royal Fleet Auxiliary
- a visiting force
The exemption does not apply to:
- construction, alteration or improvement
- dredging
- disposal of waste
What you need to do

No action required if conditions are met.

Read the full legislation in Article 36 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/36).

Air accident investigation

You do not need a marine licence for activities to recover any substance or object during an official aircraft accident investigation.

The exemption does not apply to the recovery of historic aircraft.

What you need to do

No action required if conditions are met.

Read the full legislation in Article 11 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/11).

Activities in Scottish inshore waters

You do not need a marine licence from the MMO for activities in Scottish inshore waters. These require a licence from the Scottish Government under the Marine (Scotland) Act 2010.

Scottish inshore waters extend up to 12 nautical miles off the coast of Scotland.

What you need to do

Apply to the Scottish Government if your activity is in Scottish inshore waters.

Read the full legislation in Article 38 of the Exempted Activities Order 2011 (http://www.legislation.gov.uk/uksi/2011/409/article/38).

Common exemption conditions

Navigational risk

Some exemptions only apply if the activity does not cause, and is not likely to cause, an obstruction or danger to navigation. You must be satisfied this is the case before you start.

The MMO considers that anything placed in the marine area could be a hazard. For the purposes of an exemption, a hazard becomes a danger when the risk is more than low. Even if the risk is low, you should still reduce it as far as you reasonably can.

You should seek advice on reducing navigational risk from:
- the relevant harbour authority
- Trinity House (https://www.trinityhouse.co.uk/)
- Maritime and Coastguard Agency (MCA) (https://www.gov.uk/government/organisations/maritime-and-coastguard-agency)
Check with the harbour authority first. If the activity is outside a harbour’s jurisdiction, check with the MCA or Trinity House.

Enforcement action may be taken if it is later determined that the activity caused an obstruction or danger to navigation.

Environmental Risk

Some exemptions do not apply if the activity is likely to affect protected sites, waterbodies, or the historic environment. You must be satisfied that your activity will not have these effects before going ahead.

Marine protected areas

Exemptions do not apply if the activity, alone or in combination with other plans or projects, is likely to have a significant effect on:
- a Special Area of Conservation (SAC) or Special Protection Area (SPA)
- a Ramsar site (wetlands of international importance)
- the protected features of a Marine Conservation Zone (MCZ), or the processes those features depend on
Likely means the effect cannot be ruled out using the best available evidence. An effect is significant if it undermines the site’s conservation objectives.

You cannot take mitigation measures into account when deciding whether an effect is likely. Mitigation means measures included in a proposal to avoid, reduce, or cancel an impact.

Any permanent or irreparable loss of habitat, no matter how small, will be considered a significant effect. Where this is the case, the exemption does not apply, and you must apply for a marine licence.

If you’re not sure whether your activity could affect a protected site, contact the relevant nature conservation body for advice:
- Natural England (https://www.gov.uk/government/organisations/natural-england) – for inshore waters within 12 nautical miles of the coast
- Joint Nature Conservation Committee (JNCC) (http://jncc.defra.gov.uk/) – for offshore waters
Waterbodies

Exemptions do not apply if the activity is likely to:
- prevent achievement of environmental objectives in the relevant river basin management plan
- cause environmental damage
You must be satisfied that your activity will not have these effects.

See the Environment Agency’s guidance on the Water Framework Directive (https://www.gov.uk/guidance/water-framework-directive-assessment-estuarine-and-coastal-waters) in relation to marine dredging if you’re unsure.

Enforcement action might be taken if it is later determined that the activity caused environmental damage or prevented achievement of environmental objectives.

Historic environment

Exemptions do not apply if the activity is likely to damage features of archaeological or historic interest.

This includes:
- sites, structures, buildings, artefacts and human remains with cultural, historical or archaeological value
- vessels, aircraft, vehicles or their contents in their archaeological and natural context
- objects of prehistoric character
Contact Historic England if you’re unsure whether an activity may cause damage.

Notifying MMO about an exempt activity

Many exemptions include a condition that you must notify the MMO before the activity takes place.

There are 3 types of notification:
- advance notification – you must tell the MMO before you start the activity
- approval – in some cases, you must also wait for MMO approval before beginning work
- retrospective notification – in certain emergencies, you may begin work immediately but must notify the MMO within a set period
To notify MMO of an exempt activity

Use the Get permission for marine work (https://marinelicensing.marinemanagement.org.uk/mmofox5/journey/self-service/start) service.

All new notifications will be submitted through this service from 18 November 2025.

To view previous exemptions

Use the Marine Case Management System (MCMS) (https://marinelicensing.marinemanagement.org.uk/mmofox5/journey/self-service/start) to view any exemption notifications started before 18 November 2025.