Baselines are reference lines drawn by a coastal or archipelagic State using different methods as discussed below. They are used to measure the breadth of the territorial sea (12nm), contiguous zone (24 nm), Exclusive Economic Zone (200nm) and continental shelf (up to 350nm). Also, the waters enclosed by the baselines are called archipelagic waters over which an archipelagic State exercises sovereignty.
According to the UNCLOS (United Nations Convention on the Laws of the Sea), there are three methods that can be employed in determining a State’s baselines, namely:
1. Normal Baseline, according to Art. 5, is the low-water line along the coast as marked on large-scale charts officially recognized by the coastal State.
2. Straight Baseline, according to Art. 7, can be employed if ever the coastlines are indented and cut into or there is a fringe of islands along the coast in its immediate vicinity.
3. Archipelagic Baseline, according to Art. 47, is a method of joining the outermost points of the outermost islands and drying reefs of an archipelago provided that within such baselines are included the main island and an area in which the ratio of the area of the water to the area of the land, including atolls, is between 1:1 and 9:1.
Of the three methods, the archipelagic baselines method is most applicable and advantageous to an archipelago such as ours. Otherwise, to use either the Normal or Straight baseline methods, which are primarily designed for coastal States, would effectively waive our status as an archipelagic State and lose much of the archipelagic waters as defined above.
RA 3046: as Amended by Republic Act No. 5446 or otherwise known as the Archipelagic Baselines Law of the Philippines.
RA 5446: amended RA 3046
PD 1596 (June 11, 1978) – Kalayaan Group of Islands declared by Marcos as part of our National Territory
PD 1599 (June 11, 1978) – establishes an exclusive economic zone of the Philippines extending to a distance of 200 nautical miles beyond and from the baselines from which the territorial sea is measured; except that where the limits overlap the economic zone of an adjacent state, common boundaries shall be determined by agreement with the state concerned, or in accordance with generally recognized principles of international law on delimitation.
