When politicians talk about "winning back our waters", they are more concerned about what is contained in them: fish.
Members of the European Union share a Common Fisheries Policy, where a set tonnage of specific fish - known as the Total Allowance Catch (TAC) - can be caught within EU waters and then divided between each member state.
The TAC is largely based on how much each member state fished in those areas in the 1970s, before the policy came into effect.
Splitting up the stocks is designed to keep the levels of fishing in these areas "relatively stable", and it has been found to be helping the UK's fisheries. According to Open Democracy, as fish populations decrease and produce fewer offspring, there must be an effort to reduce fishing pressure to rebuild stock, leading to larger harvests in the future.
In an analysis of the 118 years of industrial fishing in the UK, the vast majority of the fish numbers decline happened prior to the implementation of the Common Fisheries Policy.
However, it is estimated that 29 of the 33 most important commercial fish species are overfished. The EU's quota system, TAC, is a viable way to stock recovery.
Although the UK wants to take back control, EU member states already have it by being allowed to place limits on who can fish in their territorial waters.
The UK is still dominant in fishing, compared to other EU members. In 2004, it had the fourth largest catch at 652,000 tonnes. In 2014, the UK became the second largest catch with 752,000 tonnes.
Winning back the waters does not necessarily mean you will win back the fish. As the Conversation observes, fish do not "respect political boundaries". Many of the commercial species are not 'British' as mackerel, herring and cod are highly mobile and move easily across borders.
Mackerel is more of a tourist to the UK, making extensive migrations and only passing through our waters for short periods of time.
The Common Fisheries Policy is a much-maligned policy, used by Leave campaigners during the referendum as a sign of the over-bearing nature of the EU. As a member, the UK catches one of the highest tonnes of fish and benefits from the stock recovery.