The majority of states in the world – including Indonesia and Singapore – have ratified UNCLOS 1982. 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.
Four maritime zones are defined: the territorial sea, which stretches from the baseline 12 nautical miles seaward; the contiguous zone, which goes out to 24 miles; the exclusive economic zone – at 200 nautical miles, and the continental shelf, up to 350 miles or more.
The nautical mile is the unit of measurement employed in relation to the law of the sea; one mile equals 1852 metres.
Maritime zones can be claimed unilaterally as long as the claims do not infringe on other states’ maritime zones.
In the case of Indonesia and Singapore, it is impossible for Indonesia to claim the full set of maritime zones without infringing upon Singapore’s entitlements, and vice versa.
Because of their proximity to each other, Indonesia and Singapore need to delimit even their territorial seas.
The two nations have an established maritime boundary between them, which predates UNCLOS. In May 1973, they signed a territorial sea boundary agreement that defined six boundary line turning points.
The co-ordinates of the six points are expressed in latitude and longitude in the bilateral treaty. Indonesia ratified the agreement on 3 December 1973; Singapore did so almost a year later, on 29 August 1974 (The Geographer, 1974).
Since its ratification by both parties, the agreement has been legally binding. Despite this agreement, it is worth noting that neither of the two states have agreed on all the boundaries that need to be delimited.
Negotiations were initiated in 2005 to finalise the 1973 maritime boundary agreement. Talks have been conducted both in Indonesia and Singapore, but so far they have not 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 these changes have any bearing on Singapore’s maritime claims? Furthermore, will they affect the existing maritime boundary agreement?
UNCLOS Article 11, 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 has been expanded in the manual on Technical Aspects of the UNCLOS 1982. TALOS 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 the reclamation work in Singapore conforms with this definition – as it would seem to — it is quite clear that such installations can be used as part of the baseline. Singapore could, therefore, potentially move its maritime claim southward toward Indonesia.
However, there is another principle in play here: changes of baseline cannot alter an 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, Indonesia may need to anticipate the possibility that Singapore will employ a new baseline configuration as the result of reclamation. 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 does not form an integral part 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 co-ordinates of latitude and longitude, without specifying a datum, tell us nothing.
Such co-ordinates do not refer to any specific location on Earth, meaning that the maritime boundary lines that 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 (especially 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.