Black Sea · The Hague, 2009
The line in the Black Sea
Between 1998 and 2004, Romania and Ukraine held 24 rounds of negotiations on dividing the sea off the Danube Delta, without reaching an agreement. The map shows the line each country proposed. Between them lie 12,162 km² of sea that both claimed.
Draw the line yourself. Move the three white points to where it seems fair (the bottom point moves only left and right), then compare your line with the International Court of Justice’s.
What each country proposed#
Both lines start from the same place, which the judgment calls Point 1: where the limit of Romania’s territorial sea meets Ukraine’s territorial sea around Serpents’ Island. The two countries fixed it in their 2003 border treaty. Beyond it, the continental shelf and the exclusive economic zones had never been divided.
Romania proposed a line that first followed the 12-nautical-mile arc around the island to a point out at sea, then ran halfway between the two coasts, without using the island as a base point. Ukraine proposed an almost straight line to the south-east, built with the island as part of its coast.
Between the two lines lie 12,162 km² of sea, more than half the size of Wales. The area is measured down to the southern end of Romania’s proposed line. Further south, the rights of Bulgaria and Turkey could come into play, so the Court’s line stops short of them.
Step 1: the same distance from both shores#
The Court first drew a provisional equidistance line: every point on it is the same distance from the nearest base point on the Romanian coast as from the nearest on the Ukrainian coast. As base points it chose the places on the shore that reach furthest out to sea, where the coast changes direction.
It chose five. On the Romanian shore, the Sacalin Peninsula and the place where the Sulina dyke meets the land. On the Ukrainian shore, the south-eastern tip of Tsyganka Island at the mouth of the Chilia branch, then Cape Tarkhankut and Cape Khersones in Crimea. On the map, circles spread from each base point at the same speed. The line appears where the circles from the two countries meet.
At points A, B and C the base points that steer the line change: at A the Sacalin Peninsula takes over, at B Cape Tarkhankut across the sea, at C Cape Khersones. Recalculated from nothing but the coordinates printed in the judgment, the distances from each of these three points to the two coasts differ by at most 5 metres.
One detail mattered. The Sulina dyke, which protects ships entering the mouth of the Danube, runs 7.5 km out to sea. Both countries had proposed its seaward tip as a base point. The Court did not accept it, because it had not been shown that the dyke served any direct purpose for a port, and used the landward end instead.
Step 2: an island of 17 hectares#
Serpents’ Island covers 0.17 km², with a shoreline of about 2,000 metres. It stands alone at sea, some 20 nautical miles (37 km) from the Danube Delta. Ukraine asked for the island to count as part of its coast. The Court refused at the first step, when it chose the base points: the island is not part of a fringe of islands that make up a shoreline, and counting it as coast would have meant, in the judgment’s words, “a judicial refashioning of geography”.
The button below shows a simulation made for this page, in which the island is used as a base point alongside the other five. The simulated line is not the line Ukraine proposed.
In the simulation, the line runs up to 42 km from the Court’s line, and within the area both countries claimed about 4,500 km² more would fall on Ukraine’s side.
At the second step, the Court checked whether the island still called for an adjustment of the line, and decided it did not. Ukraine’s 12-nautical-mile territorial sea around the island stayed as it was, and the line follows its limit to Point 2, then continues out to sea.
It is often said that Romania won because the island was declared a rock. The judgment does not say so. The Court wrote that it did not need to decide whether the feature is an island or a rock under the UN Convention on the Law of the Sea: in the area being divided, any rights the island might generate were already covered by those of Ukraine’s mainland coast.
Step 3: the disproportion check#
Finally, the Court checked that the result was not grossly out of proportion to the lengths of the coasts. The aim is not a proportional division, only to avoid a glaring imbalance. Romania’s relevant coast measures about 248 km and Ukraine’s about 705 km: a ratio of 1 to 2.8. In the relevant area, which is larger than the area both countries claimed, the line leaves areas in a ratio of 1 to 2.1.
The Court decided the line needed no change. Along the way it had set aside other arguments: Ukraine’s, about oil and gas concessions, fishing and naval patrols in the area, and Romania’s, that the 1949 Romanian–Soviet agreements had already fixed the line along the arc around the island, as far as a point east of it (Point X).
The judgment#
On 3 February 2009 the Court adopted its judgment unanimously, with all 15 judges in favour, including the two chosen by the parties: Jean-Pierre Cot, by Romania, and Bernard Oxman, by Ukraine. Of the 12,162 km² both countries claimed, the line leaves 9,615 km² (79.1%) on Romania’s side and 2,547 km² on Ukraine’s.
Romania’s foreign ministry gives 9,700 km², or 79.34% of about 12,200 km². The areas depend on how the zone is outlined, above all on its southern limit, because the Court set no end point for the line. If the zone is closed further north, at the parallel of 43°48′, Romania’s share comes out at 76%.
The line is not a state border, and the judgment says so explicitly. It divides the zones in which each country holds sovereign rights over resources in the water, on the sea floor and beneath it: the exclusive economic zone and the continental shelf. The judgment changed neither country’s territory nor the freedom of navigation.
What lies under the water#
The map shows the shape of the sea floor. Down to about 200 metres it slopes gently: this is the shallow platform geographers call the continental shelf. Then it drops along a slope cut by canyons to more than 2,000 metres. Across 62% of the disputed area the water is less than 200 metres deep; across half of it, less than 101 metres. In the legal sense used by the judgment, though, the continental shelf covers the whole sea floor in the area, however deep.
In and near this area there is gas. Neptun Deep, the OMV Petrom and Romgaz project, will produce it from two fields: Pelican South on the shelf and Domino on the slope, about 160–175 km east of Tuzla on the Romanian coast. OMV Petrom expects first gas in 2027.
Coordinates in the project’s environmental impact report show where its installations sit relative to the two proposed lines. The platform and the Pelican South drill centre are 2–5 km from the line Ukraine proposed, on Romania’s side of it, so outside the area both countries claimed. At Domino, one drill centre is on that side too, 2–4 km from the line; the other is 1.5–3.5 km inside the disputed area. All four are 49–66 km from the Court’s line, on Romania’s side. The ranges come from Ukraine’s line itself: the bearing written in its claim, 156°, and its printed Point 3 do not quite agree. The outlines of the gas fields are not public, so it is not possible to say how much gas lies on either side.
Rockall and the UK’s fishing limits#
The rule Romania relied on has been applied in Britain too. On 21 July 1997, announcing that the UK would join the UN Convention on the Law of the Sea, Foreign Secretary Robin Cook said in a written answer to the Commons that Rockall, a bare granite islet in the North Atlantic, “is not a valid base point” for the UK’s fishing limits under article 121(3), and that the limits would be redrawn from St Kilda.
Article 121(3) says that rocks which cannot sustain human habitation or economic life of their own have no exclusive economic zone and no continental shelf. Romania relied on it to argue that Serpents’ Island could not generate zones of its own. In the Romania–Ukraine case, the Court did not need to decide the island’s status under that provision.
Serpents’ Island passed from Romania to the USSR under a protocol signed in Moscow on 4 February 1948, which the judgment quotes; the 1947 Paris peace treaty had not mentioned it. In 1949 a Soviet–Romanian border commission ran the border along the 12-nautical-mile arc around it. After the USSR broke up, the island stayed with Ukraine. The case in The Hague was not about who owns the island: the Court only had to draw the line further out, and the arc around the island, accepted by both countries, was left as it was.
On 24 February 2022, the first day of Russia’s full-scale invasion of Ukraine, Russian warships attacked the island and took it; its defenders, who had refused to surrender, were captured. Russian forces left on 30 June 2022: Ukraine said its artillery and missile strikes had driven them out, while Moscow called it “a gesture of goodwill”. The 2009 line stayed where it was.