On April 28, 2022, the International Tribunal on the Law of the Sea (ITLOS) issued a verdict in the maritime boundary dispute between Mauritius and the Maldives. The dispute involved the Exclusive Economic Zones (EEZ) of the Maldives and the Chagos archipelago, and the delimitation of territorial waters between Mauritius and the Maldives. The tribunal sided with the Maldives, awarding a bigger portion of the disputed area to the Maldives.
The origins of the dispute go back to 2019, when the United Nations General Assembly sought the International Court of Justice’s (ICJ) advice on the status of the Chagos Islands. The ICJ ruled that the islands were under Mauritius sovereignty. Later that year, the UN General Assembly adopted a resolution calling on the United Kingdom to hand over Chagos to Mauritius within six months.
Mauritius then went to the ITLOS to delimitate territorial waters from the Maldives based on the ICJ’s recommendations. The Maldives had voted against the UN resolution at the time, but in August 2022, the country’s stance was changed to that of Mauritius via a letter President Ibrahim Mohamed Solih sent to his Mauritian counterpart.
In its judgement, the ITLOS rejected Mauritius’ argument that Blenheim Reef should be considered as a base point in drawing the equidistance line. The provisional equidistance line starts, in the west, at a point of intersection between the 200 nm limits of Mauritius and the Maldives. The 200 nm limits of the Parties in the area relevant to this delimitation should be measured from the respective archipelagic baselines published by each party, with the exception of the archipelagic baselines at Blenheim Reef.
For Blenheim Reef, the 200 nm limit should be measured from the northern intersection point of the low-water line of Blenheim Reef with the 12 nm limit measured from the low-water line of Île Takamaka. The ITLOS noted that the size of the relevant area is calculated to be approximately 92,563 sqkm. The delimitation line allocates to Mauritius 45,331 sqkm and to the Maldives 47,232 sqkm.
The ratio of the areas allocated to the parties is 1:0.960 in favour of the Maldives, the judgement read. However, the ITLOS rejected Maldives’ objections over its jurisdiction over the disagreement between the two countries concerning the delimitation of the area of overlap between the claim of the Maldives to a continental shelf beyond 200 nm and the claim of Mauritius to a 200 nm zone.
The ITLOS noted that both the Maldives and Mauritius disagree as to Mauritius’ entitlement to the continental shelf beyond 200 nm. However, the entitlement of the Maldives to the continental shelf beyond 200 nm is uncontested between the parties. A separate case is ongoing at the Commission on the Limits of the Continental Shelf (CLCS) on the same issue, and the ITLOS said it will not proceed to delimit the continental shelf beyond 200 nm between Mauritius and the Maldives, as requested by Mauritius.
The ITLOS verdict brings an end to the Mauritius v Maldives EEZ dispute over the Chagos case. The ruling of the tribunal allocates a larger portion of the disputed area to the Maldives. However, the dispute over the continental shelf beyond 200 nm between Mauritius and the Maldives remains unresolved and is currently being considered by the CLCS.