On 14 March 2012, the International Tribunal for the Law of the Sea (the “ITLOS“) issued its judgment in the dispute concerning delimitation of the maritime boundary between Bangladesh and Myanmar in the Bay of Bengal.

This case, upon which Herbert Smith advised, is a significant contribution to the jurisprudence in this area.  This post highlights three key points arising out of the judgment, and examines what it may mean for the future resolution of other maritime boundary disputes.


Almost since Bangladesh’s independence in 1971, it has been in negotiation with Myanmar over their maritime boundary in the Bay of Bengal.

The Bay of Bengal is rich with hydrocarbons, some of which are now more accessible given advances in deep water exploration.  Despite many meetings to negotiate the maritime boundary, no final delimitation was agreed.

Relations between Bangladesh and Myanmar, both parties to the United Nations Convention on the Law of the Sea (“UNCLOS“), became severely strained in October 2008 when survey ships subcontracted by Daewoo, acting under licence from Myanmar, began conducting survey work close to St Martin’s Island and in a maritime area claimed by Bangladesh.  Bangladesh responded by dispatching three naval vessels leading to a stand-off between the two navies lasting over a week until the Daewoo vessels withdrew.  This incident focused attention on the maritime boundary, leading to further talks.

In the absence of agreement, however, and in the face of rising tension in the region, arbitral proceedings were commenced by Bangladesh in October 2009, pursuant to UNCLOS.  A few weeks later Myanmar deposited a “Declaration” under UNCLOS accepting the jurisdiction of the ITLOS to hear the dispute.  Bangladesh itself then lodged a similar Declaration on 12 December 2009, initiated proceedings before the ITLOS on the next day, and withdrew the separate arbitral proceedings.  Myanmar withdrew its Declaration in January 2010, presumably to prevent other proceedings being brought against it before the ITLOS.  But it was considered that this did not affect the jurisdiction of the ITLOS over the proceedings that had already commenced.

The ITLOS proceedings were broadcast by way of a “webcast” and remain available on http://www.itlos.org/.[1]

1. The ITLOS: the Sleeping Beauty of maritime dispute resolution?

States have conventionally submitted resolution of their boundary disputes to the International Court of Justice (the “ICJ“) or to arbitral tribunals.  Under UNCLOS, States are permitted to submit maritime disputes not only to the ICJ and to arbitration (in accordance with UNCLOS Annex VII and VIII) but also to the ITLOS.

Despite the prominent role it has been given under UNCLOS in interpreting and enforcing rights and obligations under UNCLOS, many of the cases before the ITLOS in its 16 year history have concerned prompt release of vessels, and to a lesser degree fishing issues (particularly of swordfish and southern blue fin tuna). Bangladesh/Myanmar was the first time that a dispute on the delimitation of a maritime boundary had been submitted to the ITLOS.

Whilst it was common ground between the Parties that the territorial sea (12 nautical miles (“NM“)) and the exclusive economic zone (“EEZ“) and “inner” continental shelf (up to 200 NM) should be delimited by the ITLOS, there was considerable debate as to whether (i) the ITLOS had jurisdiction to delimit the continental shelf beyond 200 NM and, (ii) if so, whether it should exercise that jurisdiction.

The ITLOS expressly took jurisdiction over the issue because it felt that “it would not be conducive to the efficient operation of [UNCLOS]” to do otherwise and because it felt that “it has an obligation to adjudicate the dispute and to delimit the continental shelf between the Parties beyond 200 NM“.  This was so, notwithstanding Myanmar’s December 2008 submission to the Commission on the Limits of the Continental Shelf (the “CLCS”), a separate body established under UNCLOS, and in the face of Myanmar’s objections as to the “advisability” of the ITLOS in doing so, in light of the claims of third parties (and specifically India), and rights to the international seabed area.

The ITLOS took jurisdiction because:-

  • There is but one continental shelf: UNCLOS does not distinguish between the “inner” and “outer” parts of the continental shelf.
  • Since its decision was only binding on the parties before it, namely Bangladesh and Myanmar, no prejudice could be suffered by third parties such as India.
  • It was not persuaded by the fact that the CLCS had not yet made its recommendations[2] on the submissions made by both Myanmar and Bangladesh on the outer limits of the continental shelf respectively claimed by each State.[3]  In this connection, it distinguished between its own role to “delimit” the continental shelf, and the CLCS’s role to “delineate” it – in other words, the ITLOS was content to take jurisdiction over describing the direction of the continental shelf boundary, but not to define its terminus, which it left to the CLCS.  In this way, it considered that its exercise of jurisdiction was not an “encroachment” on the functions of the CLCS.

In light of its approach, the clarity of its near unanimous judgment on delimitation beyond 200 NM (of 22 members of the ITLOS, there was one dissenting opinion), and the widening ambit of its caseload (now including the advisory opinion in the Rare Metals Case[4]), other States may be increasingly persuaded to choose the ITLOS for their maritime disputes.

As such, Bangladesh/Myanmar may mark a coming of age for the ITLOS and its role in maritime dispute resolution and in particular, those concerning maritime boundaries.

2. Endorsement of maritime delimitation methodology – greater certainty in future cases

The ITLOS noted that in relation to the delimitation of the EEZ and continental shelf, a single maritime boundary should be drawn.  It considered that no mandatory approach to delimitation existed in international law, but that over time the “equidistance/relevant circumstances” method had become the most widely adopted, subject to an assessment of whether the outcome was disproportionate.  This involves three separate stages:-

  • First, drawing a provisional equidistance line based on the geography of the States’ coasts; and
  • Second, asking whether there were any “relevant circumstances” which required that line to be adjusted to allow for an equitable result; and
  • Finally, applying the “test of disproportionality“.

In Bangladesh/Myanmar, the ITLOS considered that after constructing the provisional equidistance line, Bangladesh’s “manifestly concave” coast line was a “relevant circumstance” which necessitated adjustment of that provisional equidistance line.  Concavity will not always be taken into consideration, but “…when an equidistance line drawn between two States produces a cut-off effect on the maritime entitlement of one of those States, as a result of the coast, then an adjustment of that line may be necessary in order to reach an equitable result.”

However, it did not consider that St Martin’s Island, a “significant maritime feature by virtue of its size and population and the extent of economic and other activities“, which the ITLOS had awarded its own 12 NM territorial sea, warranted an adjustment of the provisional equidistance line; nor would the Bengal depositional system, being the “physical, geological and geomorphological connection between Bangladesh’s land mass and the Bay of Bengal” be a relevant circumstance to be taken into consideration either.

The ITLOS then endorsed the third stage in the methodology for maritime delimitation, which has emerged from the case law over a period of time.[5]  At this third stage, a tribunal must ascertain whether the delimitation line leads to “an inequitable result by reason of any marked disproportion” between the ratio of the relevant coastal lengths and the maritime areas of the respective States parties.  This tends to be a fairly general test that one side has not been treated inequitably, rather than a substantive analysis of whether a ratio is “proportionate“.  As the ITLOS noted, “mathematical precision is not required“.

After deciding that the scientific evidence presented by Bangladesh did not prevent Myanmar making a claim to the outer part of the continental shelf, the ITLOS found that no further adjustment to the equidistance line was necessary: the ratio between the total areas awarded and the ratio of the respective lengths of Bangladesh and Myanmar’s coastlines were not disproportionate.

3.  Sovereign rights over the Bay of Bengal: some uncertainties removed, but some remain

The ITLOS’s judgment helps to clarify some of the issues at stake including the sovereign rights of a large area of the EEZ and continental shelf of the Bay of Bengal.  These are directly relevant to the rights of Bangladesh and Myanmar to grant hydrocarbon exploration and production rights in those areas and will give comfort to oil companies such as ConocoPhillips, Tullow and Daewoo who have interests there.

Yet for all the clarity of the judgment, uncertainties remain.

First, a small “grey area” within 200 NM of the Myanmar coast, but on the Bangladesh side of the delimitation line, was not delimited by the ITLOS.  After considering the difficulties it presented, the ITLOS instead noted that there existed many ways for the parties to reach an agreement on this limited area, hinting perhaps at joint development or unitisation.

Second, the adjusted equidistance line extending beyond 200 NM plotted by the ITLOS does not have a terminus point – it is said to continue “until it reaches the area where the rights of third party States may be affected.”  Those rights remain a live issue.

In this regard, the status of India’s substantial claims within the Bay of Bengal remains very much unsettled.  As noted by the ITLOS, its judgment does not bind third-parties such as India (which is currently engaged in arbitral proceedings of its own with Bangladesh) and its delimitation is without prejudice to the delineation of the continental shelf to be decided upon by the CLCS.

For further information on maritime delimitations please click here to read an article written by Dominic Roughton on ‘The rights (and wrongs) of capture: international law and the implications of the Guyana/Suriname arbitration’.

[1] A number of other recent international disputes have also been broadcast over the internet, including the 2009 Abyei Area arbitration between the Government of Sudan and the Sudan People’s Liberation Movement/Army.

[2] The CLCS received a protest note from Bangladesh in July 2009, in relation to which Herbert Smith advised, after which it stopped consideration of Myanmar’s submission, citing the need for party consent to consider the submission further.  It also suggested that it would defer consideration of both sides’ submissions to take account of further developments that might arise – this case seemingly being one.

[3] The ICJ in Nicaragua v Honduras (2007) declined to delimit the outer part of the continental shelf precisely for this reason.

[4] Seabed Disputes Chamber of the International Tribunal for the Law of the Sea: Responsibilities and Obligations of States Sponsoring Persons and Entities with Respect to Activities in the Area (1 February 2011)

[5] And which was also recently adopted in the Black Sea Serpent’s Isle case before the ICJ: Romania v Ukraine (2009).  The ICJ set out in its judgment a detailed review of maritime delimitation case law and the evolution of the “equidistance/relevant circumstances” method.