In addition to the right of innocent passage, all ships and aircraft can enjoy the more extensive right of archipelagic sea lanes passage through archipelagic waters. Article 53(3) of the LOSC defines the right of archipelagic sea lanes passage:
Archipelagic sea lanes passage means the exercise in accordance with this Convention of the rights of navigation and overflight in the normal mode solely for the purpose of continuous, expeditious and unobstructed transit between one part of the high seas or an exclusive economic zone and another part of the high seas or an exclusive economic zone.
The principal elements of the right of archipelagic sea lanes passage can be summarised:
(i) As with the right of transit passage, the right of archipelagic passage applies between one part of the high seas or an EEZ and another part of the high seas or an EEZ.
(ii) All ships and aircraft enjoy the right of archipelagic sea lanes passage in such sea lanes and air routes under Article 53(2). The right of archipelagic sea lanes passage contains the rights of overflight by aircraft. In common with the right of transit passage, foreign warships and military aircraft have the right of archipelagic sea lanes passage.
(iii) Like the right of transit passage, archipelagic sea lanes passage must be the exercise of the rights of navigation and overflight solely for the purpose of continuous, expeditious and unobstructed transit.
On the other hand, as Articles 39, 40, 42 and 44 of the LOSC apply mutatis mutandis to archipelagic sea lanes passage by virtue of Article 54, ships and aircraft during their passage are under the duties provided in those provisions. Furthermore, Article 53(5) requires that ships and aircraft in archipelagic sea lanes passage shall not deviate more than 25 nautical miles to either side of such axis lines, i.e. the centre line, during passage. At the same time, this provision holds that such ships and aircraft shall not navigate closer to the coasts than 10 per cent of the distance between the nearest points on islands bordering the sea lane. There are two different interpretations with regard to this provision.
According to the first interpretation, the phrase ‘10 per cent of the distance between the nearest points on islands’ means the whole width of the channel between the bordering islands. If the channel is 40 nautical miles, for example, the two prohibited zones would each measure 4 nautical miles. As a consequence, the sea lane would be 32 nautical miles wide and a maximum deviation would be 16 nautical miles. According to this interpretation, only if the channel between islands is at least 62.5 nautical miles wide, will the full deviation of 25 nautical miles on either side of the axis line be permissible.
In the second interpretation, the formula set out in Article 53(5) means 10 per cent of the distance from the axis line to the nearest island. In this case, the narrowest channel, which allows ships and aircraft to deviate by 25 nautical miles from the axis of the sea lane, is 55.6 nautical miles wide. In 1996, Indonesia applied the 10 per cent rule in this way in designating its archipelagic sea lanes, and the Maritime Safety Committee of the IMO accepted the submission of Indonesia in 1998. Thus it would appear that this interpretation is supported by the IMO.
The archipelagic State may designate archipelagic sea lanes and air routes under Article 53(1) of the LOSC. Article 53 sets out several conditions designating such sea lanes and air routes:
(i) The sea lanes for the archipelagic passage and air routes shall traverse the archipelagic waters and the adjacent territorial sea, and shall include normal passage routes used as routes for international navigation or overflight through or over archipelagic waters, and, within such routes, so far as ships are concerned, all normal navigational channels in
accordance with Article 53(4).
(ii) Such sea lanes and air routes shall be defined by a series of continuous axis lines from the entry points of passage routes to the exit points under Article 53(5). An archipelagic State may also prescribe traffic separation schemes for the safe passage of ships through narrow channels in such sea lanes pursuant to Article 53(6). Such sea lanes and traffic separation schemes shall conform to generally accepted international regulation under Article 53(8).
(iii) In designating or substituting sea lanes or prescribing or substituting traffic separation schemes, an archipelagic State is obliged to refer proposals to the competent international organisation with a view to their adoption pursuant to Article 53(9). This provision has a parallel in Article 41(4) of the LOSC. As with Article 41(4), the competent international organisation means the IMO. In 1998, an Indonesian partial proposal for archipelagic sea lanes was adopted at the 69th session of the Marine Safety Committee of the IMO.
(iv) Article 53(10) places an obligation upon the archipelagic State to clearly indicate the axis of the sea lanes and the traffic separation schemes on charts. The provisions of the LOSC concerning the designation of archipelagic sea lanes were further elaborated by IMO General Provisions on the Adoption, Designation and Substitution of Archipelagic Sea Lanes in 1998.
(v) If an archipelagic State does not designate sea lanes or air routes, the right of archipelagic sea lanes passage may be exercised through the routes normally used for international navigation by virtue of Article 53(12). It would seem to follow that even if archipelagic sea lanes or air routes not have been designated by the archipelagic State, submarines will be able to transit the routes normally used for international navigation submerged. On the other hand, there is a concern that a dispute may be raised between user States and archipelagic States as to what ‘the routes normally used for international navigation’ are. Furthermore, non-designation of sea lanes or air routes may create confusion as to which right – the right of innocent passage or the right of archipelagic sea lanes passage – applies in the same archipelagic waters.