Inshore Vessel Monitoring System (I-VMS) devices for under-12 metre fishing vessels registered in England
Guidance to assist fishers understand the role of I-VMS and their responsibilities.
Important update - 11 June 2026
MMO is resuming the I-VMS programme, having reached an agreement with CLS UK Ltd (previously Fulcrum Maritime Systems Ltd), to supply type-approved devices to the under-12m English fleet. This decision has been made to ensure that all English vessels are fitted with type-approved devices that transmit positional data to the UK VMS Hub, in accordance with legal requirements of the licence condition.
In the meantime, our compliance and enforcement approach will remain measured and pragmatic. Our priority is to ensure fishermen can continue to operate safely and legally.
The full statement about this decision can be found on MMO’s news page.
Next steps
Eligible vessel owners must register for a Nemo device from CLS UK Ltd, which will be provided and installed at no charge to those who register by 11.59pm on Sunday 12 July 2026.
Details on how to do this will be sent by post and email to eligible fishermen, and more information can be found below in the guidance for the ‘roll-out of I-VMS’ section below, along with information for those yet to purchase a device.
Existing devices should not be removed or switched off.
Further information
Please read the ‘roll-out of I-VMS’ guidance below.
Contact the team at ivms@marinemanagement.org.uk or 01900 508618. Phone lines are open Monday to Friday, 9.00am to 5.00pm.
Guidance for the roll-out of I-VMS
The roll-out of I-VMS devices has been delivered in stages and more than 80% of the English under-12m fleet has a type-approved device installed. A licence condition was introduced in May 2025 requiring their use, and the transmission of positional data, for English vessels when at sea.
Data transmissions to the UK VMS Hub from Succorfish ‘ SC2’ devices ceased on 11 August 2025. Ensuring that vessels are fitted with devices that transmit positional data to the UK VMS Hub is being prioritised and MMO has contracted CLS UK Ltd (previously Fulcrum Maritime Systems Ltd) to supply devices to those impacted to support fishermen resume compliance with the licence condition,
Owners of vessels fitted with SC2 devices must register for a Nemo device from CLS UK Ltd, which will be provided and installed at no charge, to eligible fishermen who register by 11.59pm on Sunday 12 July 2026.
Letters and emails are being sent to eligible vessel owners with instructions on how to register for a funded device. You will need to provide the PLN of the eligible vessel to proceed, along with your vessel name and contact information. Following registration, devices will be sent to vessel owners, and the supplier will contact you directly to arrange installation by an approved engineer.
You do not need to apply for funding, but you do need to register by 11.59pm, Sunday 12 July 2026.
The cost of the device, and its installation, will be covered by MMO for those who register by the deadline above. Registering after the deadline, or missing the installation appointment without adequate notice to the supplier or engineer, could mean individuals incur charges.
Devices will carry a one-year warranty from the date of installation.
Fishermen remain responsible for the payment of airtime contracts.
Please note: If you do not receive notification from MMO to register but believe you are eligible for a replacement device, please contact our I-VMS team immediately, using the details on this page.
Further guidance for vessel owners with SC2 devices
Register for a Nemo device, supplied by CLS UK Ltd, by 12 July 2026 - see above for details.
You are reminded to check contractual obligations with the SC2 device supplier, Succorfish, regarding airtime, warranties, access to positional data and purchase of their device. SC2 devices should not be removed or switched off before the replacement Nemo device has been installed.
Data transmissions to the UK VMS Hub from SC2 devices ceased on 11 August 2025, and MMO does not have access to this data. You should still be able to access your SC2 device data on the portal / app provided by Succorfish. You can also request your data directly from the supplier.
The removal and disposal of a device is the responsibility of the vessel owner and should always be undertaken safely and in accordance with local environmental guidelines and MMO guidance, at certified WEEE recycling providers.
Guidance for those fishing in the Devon & Severn IFCA district
Vessels fishing in the Devon & Severn IFCA district are included in this roll-out and should register for a Nemo device to be compliant with the licence condition for English waters.
Please contact the IFCA directly with questions about your Rewire device.
Guidance for vessel owners without an I-VMS device
You will have to cover purchase and installation costs yourself. Details are available on the type approved devices page of gov.uk and please note that CLS UK Ltd is the only supplier of a type-approved device that is transmitting I-VMS data to the UK VMS Hub.
MMO will notify you ahead of plans to resume enforcement of the I-VMS licence condition, but you should act promptly to purchase and install a device to meet the obligations and conditions of your fishing licence. Failure to do so may result in enforcement action for non-compliance..
I-VMS legislation
I-VMS licence condition
A licence condition for English licenced vessels was introduced on 12 May 2025, under the Fisheries Act (2020). The licence condition requirements state that:
- All English under-12 metre vessels registered with a commercial fishing vessel licence must have a functioning MMO type-approved I-VMS device when undertaking a trip to sea.
- That the device is switched on and transmitting data to be received by the UK VMS Hub
- The device is not manually overridden or tampered with to prevent the transmission of data.
Enforcement of the licence condition remains measured and pragmatic at this stage of the roll-out.
Full details on the operational requirements are outlined on the I-VMS licence condition requirements guidance page.
Statutory instrument
A statutory instrument will soon be introduced by government, making a legal requirement for all vessels under 12 metres in length, both domestic and foreign, to have an inshore vessel monitoring system (I-VMS) installed and transmitting positional data to MMO, during a trip to sea in English waters.
MMO is supporting industry in preparing for these new requirements. To date, this has been achieved through device type-approval, grant funding, a staged roll-out and the introduction of a licence condition for English vessels, to ensure every fisher has the opportunity to be compliant before the new legislation is introduced.
Existing legal measures
Fishers subject to existing legislation requiring the operation of an I-VMS device, such as under IFCA or Welsh Government legislation, should already have devices and be transmitting data.
Type-approved devices
Following independent testing, two I-VMS devices are type-approved by MMO.
To comply with your licence condition, you must purchase and install a type-approved device that transmits positional data to the UK VMS Hub.
Please note that:
- CLS UK Ltd is the only supplier of a type-approved device that is transmitting I-VMS data to the UK VMS Hub.
If you have not yet purchased or installed a type-approved I-VMS device on your vessel, you should do so now to ensure that you meet the obligations and conditions of your fishing licence.
Full details on suppliers, devices and how to order can be found on the type approved devices page of gov.uk.
What is I-VMS?
Inshore Vessel Monitoring System (I-VMS) devices monitor inshore fishing activity by under-12 metre vessels. They are similar to the VMS tracking devices used by fishing vessels of 12 metres and greater and will help:
- improve the management and sustainability of our marine environment
- ensure proper fishing practices
- prevent illegal fishing
- help protect and enhance the livelihoods of fishers.
Using GPRS mobile phone signals, I-VMS devices provide positional information (such as latitude and longitude, course, speed and date and time of each positional report) which is sent to MMO’s UK VMS Hub. When a device is located outside GPRS range, the device will continue to store the positional information and submit the data once GPRS coverage next becomes available. This is different to the VMS devices used by larger vessels, which transmit data via satellite and can become expensive.
Why is I-VMS being introduced?
I-VMS data will provide more detailed information on the inshore fleet. This will help us better understand activity undertaken by the fishing industry and the full fleet in our marine environment e.g. recreational, charter, commercial, non-commercial and guardship activity.
Combined with data on catch volumes, scientific evidence of stock levels and a range of other significant data, I-VMS will enable more efficient decisions on local and national management measures and policies. It will also enable MMO to continually improve its targeted assurance activities as the clearer picture of fishing activity will help highlight which vessels are consistently complying with regulations on where and what they can fish, and those that may introduce risk to sustainable sea fisheries.
Fishers will also be able to track their own activity and better understand their fishing effort.
Data privacy
I-VMS data is accessible to all UK Fisheries Administrations and other agencies, including Inshore Fisheries and Conservation Authorities (IFCA), and can be used for a range of activity including monitoring compliance and informing evidence-based decision-making for fisheries management.
Your personal information including location information will not be accessible to other fishers or the public.
You can read the current privacy notice on the personal information charter.
Frequently Asked Questions
All of the information you need should be included on these guidance pages but there might be some areas that you require a little bit more information about.
Please read our updated FAQs and contact us if you cannot find the information you are looking for.
Contact us
Our dedicated helpline is open Monday to Friday, 9am to 5pm, by calling 01900 508618, or you can email our I-VMS Engagement and Support team at ivms@marinemanagement.org.uk.
Updates to this page
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Update to confirm notices are being sent to vessel owners impacted by ceased data transmissions from the SC2 I-VMS devices to register for a Nemo device by 12 July 2026.
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The 'important information' section has been updated to alert industry of the next stage in the I-VMS programme
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Updated notice providing interim guidance for industry, relating to I-VMS device data transmissions
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Information box updated to share information about Devon & Severn IFCA temporary measures, in response to ceased data transmissions from Succorfish SC2 I-VMS devices to the UK VMS Hub.
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Guidance updated to reflect that a licence condition is now in force for the use of I-VMS devices on licensed English vessels, under-12 metres in length, undertaking a trip to sea.
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New guidance added to support industry prepare for a new licence condition that will require the use of I-VMS devices on English registered under-12m vessels.
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I-VMS small amends
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24 May update
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Update to "Type approved devices" section
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Update 18 January 2024
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7 December update
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Small amends
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25 October update
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FAQ update
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FAQs updated.
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I-VMS update 16/08
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FAQ updated
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FAQ Update
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IVMS update
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Added - Important update - 19 June 2023
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Update as at 19 May 2023, following outcome of independent assurance testing.
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Updated to include link to announcement of independent test results - 18 May 2023
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25 April 2023 update.
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April 20 2023 update
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Update 01 December 2022.
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November update 2022
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I-VMS privacy policy 21/10/2022
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August update
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Friday 22 July update
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Update on Maritime Systems Ltd test transmissions.
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Industry update - Data transmission issue - Maritime Systems Ltd - June 1 2022
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Page updated with privacy statement
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Updates to page following reinstatement of Maritime systems to approved device list
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I-VMS updates to page
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First published.