Badan Informasi Geospasial

Bersama Menata Indonesia yang Lebih Baik

Mapping borders with Singapore

Jakarta - It seems that tension is building in the bilateral relationship between Indonesia and Singapore.

Maritime boundary issues between the two neighbouring states are the major cause of concern, which is nothing new.

One of the topics is coastal reclamation by Singapore. Will this reclamation work change the Indonesian-Singaporean maritime boundary?

Let us first recall the principles underlying international maritime boundaries.

The delimitation of international maritime boundaries is governed by the international law of the sea, where a convention called the United Nations Convention on the Law of the Sea (UNCLOS) has been established for this purpose.

UNCLOS 1982 has been ratified by the majority of states in the world, including Indonesia and Singapore.

UNCLOS explains in detail the baselines from which maritime zones are measured seaward, the types and dimensions of claimable maritime zones, and the rules for maritime boundary delimitation.

Maritime zones include the territorial sea (12 nautical miles/NM), contiguous zone (24 NM), exclusive economic zone - EEZ (200 NM), and the continental shelf (up to 350 NM or more).

The nautical mile is the unit of measurement employed in relation to the law of the sea, where 1 NM equals 1,852 meters.

Maritime zones can be claimed unilaterally as long as the claims do not infringe upon other states' maritime zones.

However, in the case of Indonesia and Singapore, it is almost impossible for Indonesia to claim the full set of maritime zones without infringing upon Singapore's entitlements, and vise versa.

Being spatially close to each other, Indonesia and Singapore need to delimit even their territorial seas.

It is worth noting that Indonesia and Singapore have an established maritime boundary between them. The two states signed a territorial sea boundary agreement on May 25, 1973, that defined six boundary line turning points.

The coordinates of the six points are expressed in latitude and longitude in the bilateral treaty. Indonesia then ratified the agreement on Dec 3, 1973, while Singapore did so about one year later on Aug 29, 1974 (The Geographer, 1974).

Since its ratification by both parties, the agreement has been legally binding.

Despite the agreement signed by Indonesia and Singapore in the early 1970s, it is worth noting that the two neighboring states have not yet agreed on all the boundaries that need to be delimited.

Negotiations were initiated in 2005 to finalise their 1973 maritime boundary agreement. Talks have been conducted both in Indonesia and Singapore, but unfortunately they have not yet produced an agreement.

Meanwhile, Singapore has been very active in reclamation and harbour development, which consequently changes the shape of its coastline, significantly moving Singapore's coastline seaward.

The question is "do changes of coastline have anything to do with Singapore's maritime claims?"

Furthermore, "will they affect the maritime boundary agreement between Indonesia and Singapore?" To answer these questions, we need to refer to UNCLOS, which was ratified by the two states in question.

It should be stressed that a maritime claim is measured from a baseline, which can be a straight baseline connecting particular points on land, or a normal baseline represented by the coastline at low tide.

The critical question is, "can the reclamation work legally change the baseline used by Singapore?" It is not easy to answer this question.

However, we have UNCLOS to help us. Article 11 of UNCLOS states that "For the purpose of delimiting the territorial sea, the outermost permanent harbour works which form an integral part of the harbour system are regarded as forming part of the coast."

This article has also been technically explained in the Manual on Technical Aspects of the UNCLOS 1982 (TALOS), which states that permanent harbour works include "permanent man-made structures built along the coast which form an integral part of the harbour system, such as jetties, moles, quays or other port facilities, coastal terminals, wharves, breakwaters, sea walls, etc.

Such harbour works may be used as part of the baseline for the purpose of delimiting the territorial sea and other maritime zones."

Provided that reclamation conducted by Singapore is to build such harbour works as are referred to in Article 11 of UNCLOS, it is quite clear that such installations can be used as part of its baseline.

Singapore could, therefore, potentially move its maritime claim southward toward Indonesia.

However, changes of baseline cannot alter any established maritime boundary.

This means that the territorial sea boundary between Indonesia and Singapore will never be changed. A change of baseline can only affect a maritime boundary that has yet to be settled.

In finalising the 1973 agreement, the possibility of Singapore employing a new baseline configuration as the result of reclamation needs to be anticipated.

I personally believe that the people involved in the negotiations have been well briefed on this issue.

However, no issue will arise if it can be proven that the reclamation work was not to build structures that form integral parts of the coastline.

This, undoubtedly, would require intensive technical and legal investigation.

Apart from the possibility of baseline changes, there is another technical issue concerning Indonesian-Singaporean maritime boundaries.

There is no specific geodetic data mentioned in the agreement. It should be noted that coordinates of latitude and longitude without specific geodetic data tell us nothing.

Such coordinates do not refer to any specific location on earth, meaning that the maritime boundary lines they delineate do not really exist.

Theoretically, it is impossible to stake out the position of a boundary turning point without geodetic data being clearly specified.

It is the responsibility of the technical experts (e.g. geodetic surveyors) to avoid such a blunder in the next maritime boundary agreement.

To sum up, settling the outstanding maritime boundaries between Indonesia and Singapore is an urgent matter.

Collaboration between technical, legal and political experts is required to achieve a comprehensive and equitable solution.

Indonesia, for its part, has to make optimum efforts to achieve the most equitable solution.

(Writer : I Made Andi Arsana, a lecturer in the Department of Geodesy and Geomatic Engineering, Gadjah Mada University, and is a researcher with the Centre for Boundary Studies, FT UGM-Bakosurtanal)