From a previous ITLOS hearing. (Photo/ITLOS)

Maldives wins EEZ dispute with Mauritius over Chagos

The delimitation line allocates to Mauritius 45,331 sqkm and to the Maldives 47,232 sqkm.

28 April 2023

An international tribunal on Friday sided with the Maldives in the dispute with Mauritius surrounding the delimitation of the maritime boundary of the Exclusive Economic Zones (EEZ) of the Maldives and the Chagos archipelago, awarding a bigger portion to the Maldives. 

In the case:

  • When the UN General Assembly sought the International Court of Justice's (ICJ) advice, in 2019, they suggested that the Chagos islands were under Mauritius sovereignty

  • In the same year, the UN General Assembly adopted a resolution calling on United Kingdom to hand over Chagos to Mauritius within six months 

Mauritius went to the International Tribunal on the Law of the Sea (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 stand was changed to that of Mauritius via a letter President Ibrahim Mohamed Solih sent to his Mauritian counterpart. This was revealed by Attorney General Ibrahim Riffath during hearings in October.

Opposition has claimed that the president's letter amounts to giving up part of the Maldives' territory.

In its judgement, ITLOS rejected Mauritius' argument that Blenheim Reef should be considered as a base point in drawing the equidistance line. 

According to the judgement:

  • 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

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.

"Thus, the ratio of the areas allocated to the Parties is 1:0.960 in favour of the Maldives," the judgement read. 

Meanwhile, 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 Special Chamber therefore considers that the portion of the continental shelf beyond 200 nm should not be seen and treated as a separate and different maritime area of the coastal state, entailing two separate disputes," the judgement read.

ITLOS, however, noted that both the Maldives and Mauritius disagree as to Mauritius’ entitlement to the continental shelf beyond 200 nm.

"On the other hand, the entitlement of the Maldives to the continental shelf beyond 200 nm is uncontested between the parties," the judgement read.

However, a separate case is ongoing at the Commission on the Limits of the Continental Shelf (CLCS) on the same issue, ITLOS said it will not proceed to delimit the continental shelf beyond 200 nm between Mauritius and the Maldives, as requested by Mauritius.