lists of geographical coordinates of points (i) concerning the baselines for measuring the breadth of the territorial sea, as contained in the Enforcement Decree of [the] Territorial Sea and Contiguous Zone Act promulgated on 20 September 1978, amended by Presidential Decree No. 24424, dated 23 March 2013, and (ii) showing the limits of the territorial sea of a part of the territory of the Republic of Korea.
The coastlines along the Yellow Sea and the South Sea are complex and there are many islands close to the shore. Therefore, territorial waters are determined by a straight line of 12 nautical miles.
Territorial waters surrounding Jeju extend 12 nautical miles from the shoreline revealed at low tide.
The Korean straight baselines have been plotted on, and this analysis is made from, Operational Navigational Chart G-10 (ONC, which is Lambert Conformal Conic projection chart with a scale of 1:1,000,000). The baseline is depicted on the attached map for illustration purpose only.
North of point 1, along South Korea’s east coast, the low-water line has been used to determine the outer limit of the territorial sea. Korea has claimed 19 straight baseline segments beginning along its southeast coast, near Pusan, enclosing all the islands and rocks off its southern and western coasts (except for Cheju-do). As shown in Table 1, 12 of these segments are 24 miles or shorter. Five of the segments are between 24 and 48 miles; and 2 segments exceed 48 miles, with the longest segment (which connects point 13-14 between Jeolmyseong Seo and Soheugsan Do off the s.w. coast) being 60.3 miles in length.
Once the baseline lengths exceed 24 miles, particularly when the features being connected are quite small (in some cases no more than rocks) and isolated, it becomes highly unlikely that the waters being enclosed are “sufficiently closely linked to the land domain to be subject to the regime of internal waters”.
The first segment (points 1-2) encloses Yongil Bay with a 6.1 mile closing line. This bay meets the requirements of an article 10 bay. Segment two (points 3-4) also encloses an article 10 bay with a 3.1-mile closing line.
Point 5 is situated on a rock less than one mile seaward of Pusan. Not only is this feature not appropriate to be included in a straight baseline system, since it is an isolated feature with no other islands in the area, there is no straight baseline segment drawn from the mainland to the rock. This gap creates an uncertainly as to where boundary is between internal waters and the territorial sea.
The island, Saeng Do, on which basepoint number 6 lies could be used in defining an article 10 bay along that part of the South Korean mainland near Pusan. From point 6 South Korea has drawn an excessive 34.9 mile baseline to Al-som (point 7), a small islet at the southern entrance of the Western Channel. From here the baseline system continues through point 8 (Kanyo Am), point 9 (Sangbaeg Do), to point 10 (Komun Do). Points 7, 8, 9, are all very small features separated by distances of 46.1 and 19.6 miles, respectively, The distance between point 9 and Komun Do, a slightly larger feature, is 14.4 miles. These features cannot be considered as fringing the Korean mainland; these points range from 12 to 29 miles distant from the mainland. A series of straight baselines could be drawn closer to the mainland where there are larger and more islands which meet the LOS Convention criteria.
Beginning at point 6, and continuing to an area landward of point 18, a valid straight baseline system could be established if the islands closer to the mainland were used. However, the baseline segments connecting points 6 to 18 are excessive. From point 6, South Korea creates baseline segments that connect isolated small features. The segment connecting point 13-14 is 60.3 miles in length, clearly an excessive length. The islands on which basepoints 7 through 23 are located may not be used to draw a straight baseline system. A 12-mile territorial sea, however, may be drawn from the low-water line of these islands.
It should be noted that the final point 23 is located on Soryeong Do and that there is no straight baseline attaching it to the mainland. Similar to basepoint 5, this creates a situation where it is unclear where the internal waters ends and the territorial sea begins.
No straight baselines have been drawn to Cheju Do, a large island situated about 50 miles south of South Korea’s mainland.
SOUTH KOREA’S TERRITORIAL SEA CLAIM
By Presidential Decree No. 9162 of 20 September 1978 and amended by Presidential Decrees No. 13463 (7 September 1991) and No. 15133 (31 July 1996) the Republic of Korea has claimed a 12-mile territorial sea. It has made modifications to its territorial sea claim in the Western Channel of the Korea Strait (see map).
Coupled with Japan’s similar decision to modify its territorial sea claim off Tsushima, situated opposite the South Korea coast, a high seas corridor has been maintained in this international strait.
Seaward from South Korea’s basepoint 5 to point 7, along a stretch of water about 46 miles this high seas corridor is approximately 22 miles wide. It is assumed that navigational and hydrographic characteristics exists in this high seas corridor allowing for safe navigation.
Straits Used For International Navigation
Part III of the LOS Convention addresses the regime of passage through straits used for international navigation. Straits connecting one part of the high seas, or exclusive economic zone (EEZ), to another part of the high seas, or EEZ, are governed by transit passage. Under the legal regime of transit passage, as specified by Section 2 of this part of the LOS Convention (articles 37-44), ships and aircraft of all States, including warships and military aircraft, enjoy the right of unimpeded passage through such straits.
Transit passage is defined in articles 38 and 39 as the freedom of navigation and overflight solely for the purpose of continuous and expeditious transit of the strait in the normal modes of operation used by ships and aircraft. This type of transit would allow submarines to transit submerged (which is not allowed through the territorial sea in the absence of coastal State consent) since that is their normal mode of operation. Surface warships would be allowed to transit in a manner consistent with sound navigational practices and the security of the force including formation steaming and the launching and recovery of aircraft.
It should be noted that the LOS Convention addresses this type of situation where a route of high seas or exclusive economic zone exists through a strait. Article 36 states:
This Part [Part III of the LOS Convention] does not apply to a strait used for international navigation if there exists through the strait a route through the high seas or through an exclusive economic zone of similar convenience with respect to navigational and hydrographical characteristics; in such routes, the other relevant Parts of this Convention, including the provisions regarding the freedoms of navigation and overflight, apply.
Should the navigational and hydrographic characteristics for safe navigation not be present, then transit passage rights would prevail for those parts of that strait in accordance with Part III.
Prior Notification/Authorization of Warships to Enter the Territorial Sea
One further aspect of South Korea’s territorial sea claim deserving comment is its requirement in Article 4 of Presidential Decree 15133 that a foreign warship or other government ship operated for non-commercial purposes give notification and receive authorization prior to entering and transiting Korea’s territorial sea in accordance with its Territorial Sea and Contiguous Zone Act. There is no provision in the LOS Convention for a coastal State to place any notification or authorization requirements on any type of vessel to enter the territorial sea for the purpose of conducting innocent passage.
