As a fellow thalassophile, you’ll appreciate why our planetary home is sometimes referred to as ‘the blue planet’. Viewed from space, blue is the dominant colour in the marble-like swirls of greens, browns and grey-whites. We ocean lovers (aka thalassophiles, from the Greek ‘thalassa’ for sea or ocean and ‘phile’ for lover of) are also aware our cherished marine habitat covers about 70% of the Earth’s surface.

However, you’d be forgiven for not recalling that over 50% of our planet’s surface is accounted for by ‘High Seas’. High Seas refer to all waters lying beyond the areas under any national jurisdiction – so, not just the place where colourful pirates of old used to hang out. Of supreme significance is that these High Seas have a special legal status providing protections for the benefit of every man, woman and child worldwide, for now and the future. This is because High Seas are one of the five ‘international spaces’, the others being outer space, the atmosphere, Antarctica, and the seabed/sub-seabed under the High Seas.

International spaces are agreed in international law to be the ‘common heritage of humanity’, a legal principle which seeks to protect, respect and fulfill the interests of all individual citizens independently of any politically-motivated sovereign state, commercial entity or other myopic organisation. This is important intel, if we are to be effective in influencing the health of our precious, vulnerable and fast-changing oceans.

High Seas are in a way defined by what they are not! So let’s take a quick step back before we get into the meat and potatoes of improving protections for them, and remind ourselves who has what rights and where. If we were to head out to sea from any coast, for the first 12 nautical miles* (22.22 kilometres) we’d be within the ‘national territorial waters’ of the sovereign state whose coast we set off from. The state has full sovereignty, from the under the seabed, upwards through the water column, to the water’s surface; and it has the right to exploit any/all the natural resources in the water column (fish stocks, for example) and those under the seabed (like minerals and hydrocarbons).

And what happens, you may ask, where the waters are less than 24 nautical miles wide between states, like the 18 nautical mile wide Strait of Dover in the Channel/La Manche? The states’ boundary line is simply drawn down the middle, with each party having  half of the total distance.

Many countries with seaboards have gone on to secure additional specified sovereign rights (i.e. not full sovereignty), that can extend up to 200 nautical miles offshore, such areas being known as Exclusive Economic Zones. The shape of the UK’s EEZ is not an exact amplification of its terrestrial territory, but a squished version due to the overlapping 200 nautical miles claims from nearby Norway, Faroe Islands, Ireland, France, Belgium, Netherlands and Denmark. Again, the boundary line ensures each party gets half of any 200 nautical miles areas that overlap. EEZ rights include exploitation of the living marine resources in the water column and mineral/hydrocarbon resources on and below the seabed.

Realising the potential value of hitherto unexploited resources, many countries are now applying for EEZs; and some are also making claims for Extended Continental Shelf zones (based on the seabed morphology and geology extending from their coastlines), through the relevant committee run by the UN Convention on the Law of the Sea; for example, Russia, Norway, Canada, Greenland and Iceland have/are doing so in the Arctic Ocean region. ECS zones give exclusive rights to exploit seabed minerals and sub-seabed resources – but give no exclusivity for exploitation within the water column.