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Annex VII Arbitral Tribunal delimits maritime boundary between Bangladesh and India in the Bay of Bengal

Volterra Fietta Client Alert
16 July 2014

On 7 July 2014, a tribunal established under Annex VII of the United Nations Convention on the Law of the Sea (the “Tribunal”) delivered its award in the Dispute concerning the Maritime Boundary between Bangladesh and India (Bangladesh v. India) (the “Award”). The Tribunal delimited the maritime boundary between the territorial sea, the exclusive economic zone (“EEZ”) and the continental shelf within and beyond 200nm of the People’s Republic of Bangladesh (“Bangladesh”) and the Republic of India (“India”) in the Bay of Bengal. When combined with the 2012 judgment of the International Tribunal for the Law of the Sea (“ITLOS”) in the parallel delimitation dispute between Bangladesh and Myanmar, the Award brings to an end decades of uncertainty as to the allocation of maritime entitlements within the Bay of Bengal.

The Award makes an important contribution to jurisprudence on maritime boundary delimitation. In particular, the Award significantly develops the law regarding the delimitation of the continental shelf beyond 200nm.


Bangladesh and India have adjacent coasts in the Bay of Bengal in the north-eastern Indian Ocean. Each has ratified the United Nations Convention on the Law of the Sea (“UNCLOS”). Having failed to agree on maritime boundary delimitation through negotiations, Bangladesh instituted arbitral proceedings against India pursuant to Annex VII of UNCLOS on 8 October 2009. Bangladesh also instituted Annex VII arbitration against Myanmar regarding the delimitation of their maritime boundaries on the same day, but that case was transferred to ITLOS in December 2009. ITLOS delivered its judgment in the Bangladesh/Myanmar case on 14 March 2012.
The Tribunal in the Bangladesh v. India case consisted of Judge Thomas Mensah (appointed by Bangladesh), Dr. Pemmaraju Sreenivasa Rao (appointed by India), Professor Ivan Shearer, Judge Jean-Pierre Cot and Judge Rüdiger Wolfrum (appointed by the President of ITLOS). The three ITLOS judges of the Tribunal had also participated in the ITLOS decision in the Bangladesh/Myanmar case. India did not contest the jurisdiction of the Tribunal to settle the dispute.

The Judgment

Starting point of the maritime boundary
The Parties agreed that the land boundary between the two States was to be used as the starting point of the maritime boundary and that the land boundary terminus should be determined by the application of the Award of the Bengal Boundary Commission of 1947 (“Radcliffe Award”). However, the Parties disagreed on what point represented the land boundary terminus under the Radcliffe Award. The Tribunal concluded that the land boundary terminus was to be located at the “midstream of the main channel” of the Haribhanga River. On the basis of a series of contemporaneous maps (including the map used in the Radcliffe Award), the Tribunal concluded that the position of the land boundary terminus is 21° 38′ 40.2″N, 89° 09′ 20.0″E (WGS-84). The Tribunal held that an exchange of letters between civil servants of the Governments of Bangladesh and India was not sufficiently authoritative to constitute a subsequent agreement on the interpretation of the Radcliffe Award within the meaning of Article 31(3)(a) of the Vienna Convention on the Law of Treaties.

Low Tide Elevations as Base Points

Bangladesh challenged several of India’s proposed base points on the grounds that they were located on alleged low tide elevations (“LTEs”), the existence of which Bangladesh disputed. In particular, Bangladesh claimed that South Talpatty/New Moore Island had permanently disappeared below the surface by the early 1990s. The Tribunal held that, while LTEs may be used as base points for measuring the breadth of the territorial sea, it did not necessarily follow that they were appropriate base points for use by a tribunal delimiting a maritime boundary. The site visit had not confirmed whether South Talpatty/New Moore Island constituted an LTE but, in any event, the Tribunal held that it was not a suitable geographical feature for the location of a base point for delimitation purposes.

The Delimitation
The Tribunal delimited the territorial sea using the equidistance method, finding that there were no special circumstances justifying a deviation from the equidistance line approach. Regarding the delimitation of the EEZ and the continental shelf, the Tribunal considered that the three-stage equidistance/relevant circumstances method was the appropriate method to be adopted in the circumstances, in pursuit of an equitable solution. The Tribunal accordingly constructed a provisional equidistance line and then considered the relevant circumstances asserted by the Parties.

First, Bangladesh claimed that as the coastline of the Bengal Delta is highly unstable this constituted a “special circumstance” warranting the adjustment of the provisional equidistance line. The Tribunal acknowledged that the coastline was unstable, but did not consider this instability to be a relevant circumstance justifying adjustment of the provisional equidistance line. Second, Bangladesh argued that the “double concavity” of its coastline constituted a relevant circumstance. The Tribunal concluded that, as a result of the concavity of the coast, the provisional equidistance line produced a “cut-off effect” on the seaward projections of the coast of Bangladesh. The Tribunal considered that this circumstance necessitated adjustment of the provisional equidistance line in Bangladesh’s favour. Finally, Bangladesh argued that the dependency of its people on fishing in the Bay of Bengal required further adjustment of the provisional equidistance line. However, the Tribunal concluded that Bangladesh had not submitted sufficient evidence of its dependence on fishing in the Bay of Bengal to justify any adjustment of the provisional equidistance line on that basis.

The Tribunal applied the same methodology within and beyond 200nm, adjusting the provisional equidistance line into a simpler straight line to avoid a cut-off effect arising from the concavity of Bangladesh’s coast. At the final stage of the delimitation process, the Tribunal assessed the proportionality of the allocation of maritime zones by reference to the overall geography of the area, finding that no alteration of the adjusted equidistance line was required. The delimitation effected by the Tribunal is illustrated below.


The Continental Shelf beyond 200nm: questions of jurisdiction and the role of the CLCS
Bangladesh and India both claimed continental shelf entitlements beyond 200nm and had made submissions to the Commission on the Limits of the Continental Shelf (“CLCS”) with regard to the outer limits of their continental shelves. The CLCS had deferred consideration of both submissions due to the ongoing dispute between the Parties. The Tribunal held that it had jurisdiction to delimit the continental shelf beyond 200nm, citing with approval the statement of the Annex VII tribunal in the Barbados/Trinidad and Tobago case that “there is in law only a ‘single’ continental shelf rather than an inner continental shelf and a separate extended or outer continental shelf.”1 The Tribunal noted that neither Party denied the existence of a continental shelf beyond 200nm in the Bay of Bengal. The Tribunal also emphasized the distinction between the role of dispute resolution procedures under Part XV of UNCLOS and that of the CLCS, considering that if it were to decline jurisdiction over the delimitation of the continental shelf beyond 200nm, the dispute would remain unresolved, failing an agreement of the Parties.

The Grey Area
The delimitation line drawn by the Tribunal created a so-called ‘grey area’ beyond 200nm of Bangladesh’s coast but within 200nm of the coast of India. Since Bangladesh has no EEZ rights beyond 200nm, the delimitation line beyond that point only delimits overlapping continental shelf claims (that is the overlap between Bangladesh’s continental shelf beyond 200nm and India’s continental shelf within and beyond 200nm). As a result, east of the delimitation line in the grey area, Bangladesh has sovereign rights to explore the continental shelf and to exploit the “mineral and other non-living resources of the seabed and subsoil together with living organisms belonging to sedentary species”, while India has sovereign rights to the EEZ in the superjacent waters. The Tribunal left it to the Parties to determine practical arrangements for the exercise of their respective rights in the grey area.

A similar ‘grey area’ was created by ITLOS in the Bangladesh/Myanmar case, where the seabed of the grey zone is Bangladesh’s continental shelf and the superjacent waters constitute Myanmar’s EEZ. The grey area created by the Bangladesh v. India decision overlaps in part with the grey area described in Bangladesh/Myanmar, as illustrated in the map below. Within the overlap of grey areas, both decisions recognise Bangladesh’s rights over the continental shelf, whereas India and Myanmar’s rights to the EEZ overlap. The Tribunal noted that “the present delimitation does not prejudice the rights of India vis-a-vis Myanmar in respect of the water column in the area where the exclusive economic zone claims of India and Myanmar overlap.” This is in line with the statement earlier in the Award that “the Tribunal must consider the Judgment of the International Tribunal for the Law of the Sea as res inter alios acta.”


India’s appointee on the Tribunal, Dr. Rao, issued a separate Concurring and Dissenting Opinion, agreeing with the majority on the delimitation of the territorial sea and the identification of suitable base points for the construction of a provisional equidistance line in the EEZ and the continental shelf, but disagreeing with the adjustment of the equidistance line on the basis of the concavity of the coastline. He strongly disagreed both as a matter of law and policy with the creation of a ‘grey area’ as a result of the adjustment the majority made to the provisional equidistance line.


The Tribunal appears to have closely followed the approach taken (and result arrived at) in the Bangladesh/Myanmar ITLOS judgment – no doubt in part because of the substantial overlap in constitution of the two bodies. In particular, the Tribunal has confirmed the extension of the three-stage approach, including its preference for equidistance as a starting point, to overlapping outer continental shelf areas despite the fact that entitlement beyond 200m is not based on distance but on physical characteristics. Bangladesh had initially argued that it was entitled to a greater area of the outer continental shelf than India due to geological and geomorphological factors but withdrew this argument following the judgment of ITLOS in the Bangladesh/Myanmar case. The Award finalises Bangladesh’s maritime boundaries in the Bay of Bengal, simply leaving India and Myanmar to delimit their outer continental shelf boundaries and the CLCS to issue its recommendations on the outer limits of the continental shelves of India, Bangladesh and Myanmar.

(1) Robert Volterra and Stephen Fietta acted as counsel for Barbados in the Barbados/Trinidad and Tobago arbitration, which was the first ever maritime delimitation conducted pursuant to the UNCLOS Annex VII arbitral procedures.