In 2016, Forces News was given unique access to the Royal Navy's fishery protection mission.
Now known as the Overseas Patrol Squadron, its aim is to patrol fishery limits of England, Wales and Northern Ireland, helping to protect the British fishing industry and maritime economy, according to the Navy.
Our reporter, Rebecca Ricks, spent time on board Batch 1 River-class vessel HMS Severn as she policed those fishery limits.
What is the Overseas Patrol Squadron?
Based at Portsmouth Naval Base, the Overseas Protection Squadron (OPS) is the oldest frontline squadron in the Royal Navy.
The squadron protects the hundreds of thousands of tonnes of fish landed by the UK fleet, worth almost £700m, and has responsibility for 80,000 square miles of sea.
This task is fulfilled by four River-class offshore patrol vessels and one helicopter.
It is the job of the OPS to patrol the UK's Exclusive Economic Zone – the internationally agreed area in which the UK can use resources from the ocean.
And it is the squadron's job to prevent overfishing and raiding by foreign vessels, as well as enforcing fishing quotas.
The squadron also has secondary duties which include maritime counter-terrorism, counter-drug surveillance and pollution control.
They are also responsible for conducting inspections of all fishing vessels in UK waters and acting as a mediator when disputes occur between rival ships.