CHAPTER V - The Delimitation of the
International Boundary
The Tribunal's Comments on the Arguments of the Parties
113.
Since, as it will appear below, the international maritime boundary line decided
upon by the Tribunal differs in some respects from both the one claimed by
Yemen and the one, or the ones, claimed by Eritrea, it is right first to
explain briefly where and why the boundaries claimed by the Parties have not
been endorsed in this Award. This will now be done taking generally first the
Yemen claim and then the Eritrean claim, as this was the order in which the
Parties agreed to argue in the Oral Proceedings of this Second Stage of this
Arbitration.
114.
Yemen claimed one single international boundary line for all purposes. The
single line it claimed was described as a "median line", because
Yemen treated the westward-facing coasts of all of its islands as relevant
coasts for purposes of the delimitation. For the Eritrean coast, Yemen used
base points on the mainland coast of Eritrea and thus ignored the Eritrean
mid-sea islands for the purpose of delimitation of the boundary. Yemen also
claimed that its line can properly be described as a coastal median line. For
Yemen the relevant coasts included not only the islands over which it has been
awarded sovereignty, but also of certain among the Dahlak islands; thus Yemen,
like Eritrea, was prepared to treat the Dahlaks as being part of the Eritrean
coast, and so used base points on the islets forming the outer fringe of the
group. When on the other hand Eritrea spoke of what it called "the coastal
median line", it meant the median line between what in the Eritrean view
represented the mainland coasts of both Parties. At the same time
Eritrea claimed a historic median line using only its own islands as base
points, and thus ignoring those of Yemen. These variations produced different
claimed median lines. See Eritrea's Maps 3 and 7, and Yemen's Map 12.1. See
also Charts 1 and 2 showing the base points as provided by Eritrea.
115. It
is in what Yemen called the northern sector of the boundary line where this
difference caused the greatest divergence, actually of several nautical miles,
between the lines claimed by the Parties because of the question of how much
"effect" on the line should be given to the Yemen northern islands,
namely the small sole mid-sea island of Jabal al-Tayr and the mid-sea groups of
islands and islets called Zubayr. Yemen allowed them full effect on the line;
Eritrea's line allowed them none.
116. In
considering this marked divergence of view it is well to recollect that the
boundary line in its northern stretch - including indeed both the opposing
claimed lines - are boundaries between the Yemen and the Eritrean continental
shelves and EEZ; and are therefore governed by Articles 74 and 83 of the 1982
Convention. In any event there has to be room for differences of opinion about
the interpretation of articles which, in a last minute endeavour at the Third
United Nations Conference on the Law of the Sea to get agreement on a very
controversial matter, were consciously designed to decide as little as
possible. It is clear, however, that both Articles envisage an equitable result.
117.
This requirement of an equitable result directly raises the question of the
effect to be allowed to mid-sea islands which, by virtue of their mid-sea
position, and if allowed full effect, can obviously produce a disproportionate
effect - or indeed a reasonable and proportionate effect - all depending on
their size, importance and like considerations in the general geographical
context.
118.
Yemen understood this problem very clearly. Its argument was that, although
these mid-sea islands and islets are small and uninhabitable (these questions
figured prominently in the First Stage of this Arbitration), those
considerations were nicely matched, or "balanced", by the
complementary smallness and lack of importance of the outer islets of the
Dahlak group which were the base points on the Eritrean side of the boundary.
However, the situation of these Dahlak islets is very different from that of
the mid-sea islands. The Dahlak outer islets are part of a much larger group of
islands which both Parties were agreed are an integral part of the Eritrean mainland
coast. Consequently, between these islets and the mainland, the sea is Eritrean
internal waters. The Tribunal had therefore, as will be seen below, no
difficulty in rejecting this "balancing" argument of Yemen, as it
does not compare like with like.
119. In
its assessment of the equities of the "effect" to be given to these
northern islands and islets, the Tribunal decided not to accept the Yemen plea
that they be allowed a full, or at least some, effect on the median line. This
decision was confirmed by the result that, in any event, these mid-sea islands
would enjoy an entire territorial sea of the normal 12 miles - even on their
western side.
120.
One practical result of the Yemen balancing argument regarding the northern
mid-sea islands is that Yemen did not argue in the alternative about possible
base points on the islands fringing the Yemen mainland coast - which
islands could much more cogently be said to balance the Dahlaks.
121.
The Eritrean argument concerning this northern stretch of the line was
relatively simple: it argued strongly against the Yemen balancing suggestions,
and here asked for the mainland coastal median line. At first, it was not clear
what were the base points used by Eritrea. However, in answer to a question
from the Tribunal, Eritrea did produce two complete sets of base points for the
Eritrean coast and also a set for the Yemen coast. (See Charts 1 and 2.)
122.
The latitude of 1425N - where the Yemen northern sector becomes the Yemen
central sector - results from another factor on which the Parties differ. This
line of latitude is not chosen at random by Yemen. It is the point at which the
Yemen median line is no longer controlled by Zubayr as a base point but enters
under the control of the north-western point of the island of Zuqar. The
Eritrean lines, for indeed there are two of them, continue southwards, ignoring
the possible effect of the Zuqar - Hanish group. The "historic"
median line (Map 3) cuts through Zuqar, and the coastal median line cuts
through the island of Greater Hanish (Map 7).
123.
The Tribunal did not find it easy to resolve this divergence of method, but
finally the Tribunal decided to continue its line as a mainland coastal line
until the presence of Yemen's Zuqar-Hanish group compels a diversion westwards.
(The Tribunal's line, as will appear below, is neither the Yemen line nor yet
the Eritrean line.)
124. In
support of its enclave solution for certain of the Eritrean islands, Yemen
entered upon an assessment of the relative size and importance of the Eritrean
islands generally, as if they were islands whose influence on the boundary line
falls to be assessed, not as being possibly in an area of overlapping
territorial sea, but as if they were to be assessed solely by reference to
Articles 74 and 83 of the Convention. This approach enabled Yemen to argue that
these Eritrean "navigational hazards" were insignificant even when
compared with the Yemen Zuqar-Hanish group; and that accordingly the South West
Rocks and the Haycocks ought to be enclaved and the boundary line taken onto
the Eritrean side of them, thus leaving the two enclaves isolated on the Yemen
side of the boundary line.
125.
The Tribunal, as will appear below, has had little difficulty in preferring the
Eritrean argument, which brings into play Article 15. This solution also has
the advantage of avoiding the need for awkward enclaves in the vicinity of a
major international shipping route.
126.
The Yemen "southern sector" began at the line of latitude 1320N.
Again, this is not an arbitrary choice. It was the point at which Yemen's
median line, which had hitherto been controlled by Suyul Hanish, first came
under the control of the nearest point on the mainland coast of Yemen. The
Yemen line then continued throughout the southern sector as a coastal median
line.
127. In
the main part of this southern sector, therefore, there were only differences
of detail between the Yemen and Eritrean lines because there were no mid-sea
islands to complicate the problem. There was indeed the large complication of
the Bay of Assab and of its off-lying islands, but here Yemen rightly assumed
that this bay is integral to the Eritrean coast and is internal waters, and
that the controlling base points would therefore be on the low-water line of
the outer coastal islands.
128. In
the course of its passage from the overlapping territorial seas areas to the
relatively simple stretch between parallel coasts of the southern sector, the
Yemen line was again a median line controlled by the Yemen islands as well as
by the Eritrean mainland coast. However, the line preferred by the Tribunal,
mindful of the simplicity desirable in the neighbourhood of a main shipping
lane, is one that would mark this passage directly and independently of the
Yemen and Eritrean islands. It is not easy to trace the Eritrean median line in
this area because of the complication of its box system for the traditional
fishing areas. Indeed, this review of the Parties' arguments and the Tribunal's
view of them does somewhat scant justice to the complicated and carefully
researched Eritrean scheme for delimitation of the traditional fishing areas,
but this matter has been dealt with in Chapter IV.
This
chapter will now turn to describe the boundary line determined by the Tribunal.
* * *
The
Boundary Line Determined by the Tribunal
129.
The task of the Tribunal in the present Stage of this Arbitration is defined by
Article 2 of the Arbitration Agreement, and is to "result in an award
delimiting the maritime boundaries". The term "boundaries" is here
used, it is reasonable to assume, in its normal and ordinary meaning of
denoting an international maritime boundary between the two State Parties to
the Arbitration; and not in the sense of what is usually called a maritime
"limit", such as the outer limit of a territorial sea or a contiguous
zone; although there might be places where these limits happen to coincide with
or be modified by the international boundary.
130.
Article 2 also provides that, in determining the maritime boundaries, the
Tribunal is to take "into account the opinion it will have formed on
questions of territorial sovereignty, the United Nations Convention on the Law
of the Sea, and any other pertinent factor". The reasons for taking
account of the Award on Sovereignty are clear enough and both Parties have
agreed in their pleadings that, in the Second Stage, there can be no question
of attempting to reopen the decisions made in the First Award. The requirement
to take into account the United Nations Convention on the Law of the Sea of
1982 is important because Eritrea has not become a party to that Convention but
has in the Arbitration Agreement thus accepted the application of provisions of
the Convention that are found to be relevant to the present stage. There is no
reference in the Arbitration Agreement to the customary law of the sea, but
many of the relevant elements of customary law are incorporated in the
provisions of the Convention. "Any other pertinent factors" is a
broad concept, and doubtless includes various factors that are generally
recognised as being relevant to the process of delimitation such as
proportionality, non-encroachment, the presence of islands, and any other
factors that might affect the equities of the particular situation.
131. It
is a generally accepted view, as is evidenced in both the writings of
commentators and in the jurisprudence, that between coasts that are opposite to
each other the median or equidistance line normally provides an equitable
boundary in accordance with the requirements of the Convention, and in
particular those of its Articles 74 and 83 which respectively provide for the
equitable delimitation of the EEZ and of the continental shelf between States
with opposite or adjacent coasts. Indeed both Parties to the present case have
claimed a boundary constructed on the equidistance method, although based on
different points of departure and resulting in very different lines.
132.
The Tribunal has decided, after careful consideration of all the cogent and
skilful arguments put before them by both Parties, that the international
boundary shall be a single all-purpose boundary which is a median line and that
it should, as far as practicable, be a median line between the opposite
mainland coastlines. This solution is not only in accord with practice and
precedent in the like situations but is also one that is already familiar to
both Parties. As the Tribunal had occasion to observe in its Award on
Sovereignty (paragraph 438), the offshore petroleum contracts entered into by
Yemen, and by Ethiopia and by Eritrea, "lend a measure of support to a
median line between the opposite coasts of Eritrea and Yemen, drawn without
regard to the islands, dividing the respective jurisdiction of the
Parties". In the present stage the Tribunal has to determine a boundary
not merely for the purposes of petroleum concessions and agreements, but a
single international boundary for all purposes. For such a boundary the
presence of islands requires careful consideration of their possible effect
upon the boundary line; and this is done in the explanation which follows. Even
so it will be found that the final solution is that the international maritime
boundary line remains for the greater part a median line between the mainland
coasts of the Parties.
133.
The median line is in any event some sort of coastal line by its very
definition, for it is defined as a line "every point of which is
equidistant from the nearest points on the baselines from which the breadth of
the territorial seas of the two States is measured" (Article 15 of the
Convention), although the same definition will be found in many maritime
boundary treaties and also in expert writings. The "normal" baseline
of the territorial sea as stated in Article 5 of the Convention - and this
again accords with long practice and with the well established customary rule
of the law of the sea - is "the low-water line along the coast as marked
on large scale charts officially recognised by the coastal State". There
do arise some questions about what is to be regarded as the "coast"
for these purposes, especially where islands are involved; and these questions,
on which the Parties differ markedly, require decisions by the Tribunal.
134.
First, it is necessary to deal with a complication that arises in the present
case concerning this general rule of measuring from the low-water line. The
domestic legislative definition of the territorial sea of Eritrea is still the
1953 enactment by Ethiopia which fixed Ethiopia's territorial waters as
"extending from the extremity of the seaboard at maximum annual high
tide". This was done even though an Ethiopian customs enactment of 1952
had provided for a customs zone measured from the "the mean low-water mark
at neap tides". The Yemen claim was that, in view of this 1953
legislation, the Tribunal should measure the median line boundary from the
high-water line instead of the low-water line along the Eritrean coast (and
indeed Yemen's median line does).
135. In
this matter the Tribunal prefers the Eritrean argument that the use of the
low-water line is laid down by a general international rule in the Convention's
Article 5, and that both Parties have agreed that the Tribunal is to take into
account the provisions of the Convention in deciding the present case. The
median line boundary will, therefore, be measured from the low-water line,
shown on the officially recognised charts for both Eritrea and Yemen, in
accordance with the provision in Article 5 of the Convention. The officially
recognised charts used by the Tribunal are BA (British Admiralty) Charts; those
Charts use as a Chart Datum approximately the level of the Lowest Astronomical
Tide. These Charts were among those relied on by the Parties in the present
Stage of the Proceedings.
Northern
and Southern Extremities of the Boundary Line
136.
There is also a problem relating to both the northern and the southern
extremities of the international boundary line. The Tribunal has the competence
and the authority according to the Arbitration Agreement to decide the maritime
boundary between the two Parties. But it has neither competence nor authority
to decide on any of the boundaries between either of the two Parties and
neighbouring States. It will therefore be necessary to terminate either end of
the boundary line in such a way as to avoid trespassing upon an area where
other claims might fall to be considered. It is, however, clearly necessary to
consider the choices of the base points controlling the median line first, and
then to look at the cautionary termination matter when the line to be thus
terminated at its northern and southern ends has been produced.
137.
The construction of the international single boundary decided upon by the
Tribunal, working generally from the north to the south, will now be described.
The
Northernmost Stretch of the Boundary Line
138.
In this stretch, where the two lines claimed respectively by Eritrea and Yemen
differed so markedly in their courses, there were three main problems: what to
do about the Dahlak islands on the Eritrean side; what to do about the lone
mid-sea island of Jabal al-Tayr and the mid-sea island group of Jabal
al-Zubayr; and what to do about the cluster of islands and rocks off the
northern coast of Yemen. These three questions will now be considered in that
order.
The
Dahlaks
139.
This tightly knit group of islands and islets, or "carpet" of islands
and islets as Eritrea preferred to call it, of which the larger islands have a
considerable population, is a typical example of a group of islands that forms
an integral part of the general coastal configuration. It seems in practice
always to have been treated as such. It follows that the waters inside the
island system will be internal or national waters and that the baseline of the
territorial sea will be found somewhere at the external fringe of the island
system.
140. A
problem that arises here, however, is that the Dahlak fringe of coastal islands
is also suitable for the application not of the "normal baseline" of
the territorial sea, but of the "straight baselines" described in
Article 7 of the Convention (as there distinguished from the "normal"
baseline described in Article 5). The straight baseline system is there
described as "the method of straight baselines joining appropriate
points". Yemen appears to have little difficulty in agreeing that the
Dahlaks form an appropriate situation for the establishment of a straight
baseline system.
141.
Eritrea for its part claimed that it has such a system already established. In
answer to a question from the Tribunal, Eritrea did give the coordinates for
the base points on the Eritrea side for both versions of its claimed
"median line". But these base points in the region of the Dahlaks
appear to have been located on a line touching two or perhaps three of the
outer islands and the Negileh Rock (for which see below paragraphs 146-147) and
then continuing in a more or less straight line out to sea in a south-easterly
direction. This scheme is probably part of the "quadrilateral"
straight baseline system to which Eritrea referred in argument.
142.
The reality or validity or definition of this somewhat unusual straight
baseline system said to be existing for the Dahlaks is hardly a matter that the
Tribunal is called upon to decide. The Tribunal does however have to decide on
the base points which are to control the course of the international boundary
line. In plotting its own claimed median line boundary, Yemen has employed as
its western base points the high-water line of the small outer islets of
Segala, Dahret Segala, Zauber and Aucan. These islets could reasonably be
included in a straight baseline system of the ordinary and familiar kind.
143.
Eritrea, however, has in particular suggested a feature called the
"Negileh Rock" which lies further out than these larger but still
small and uninhabited islets. Yemen objected to the use of this feature by
reason of the fact that on the BA Chart 171 this feature is shown to be a reef
and moreover one which appears not to be above water at any state of the tide.
A reef that is not also a low-tide elevation appears to be out of the question
as a base point, because Article 6 of the Convention (which is headed
"Reefs") provides:
In the case of islands situated on atolls or of
islands having fringing reefs, the baseline for measuring the breadth of the
territorial sea is the seaward low-water line of the reef, as shown by the
appropriate symbol on charts officially recognized by the coastal State.
144.
This difficulty about the Negileh Rock is reinforced if there is indeed a
straight baseline system in existence for the Dahlaks, for paragraph 4 of
Article 7 provides:
4. Straight baselines shall not be drawn to and from
low-tide elevations, unless lighthouses of similar installations which are
permanently above sea level have been built on them or in instances where the
drawing of straight baselines to and from such elevations has received general
international recognition.
145.
Although Eritrea is not a party to the Convention; nevertheless it has agreed
to its application in the present case; and since Eritrea claims the existence
of a straight baseline system, that claim seems to foreclose any right to
employ a reef that is not proud of the water at low-tide as a baseline of the
territorial sea.
146. As
will appear more particularly below, the Tribunal has decided that the western
base points to be employed on this part of the Eritrean coast shall be on the
low-water line of certain of the outer Dahlak islets, Mojeidi and an unnamed
islet east of Dahret Segala.
* * *
Next,
it is necessary to decide on the treatment of the mid-sea islands of al-Tayr
and Zubayr, for on this decision depends the question of whether it will be
necessary to consider base points on the coast of Yemen.
Jabal
al-Tayr and the Zubayr Group
147.
Yemen employed both the small single island of al-Tayr and the group of islands
called al-Zubayr as controlling base points, so that the Yemen-claimed median
line boundary is "median" only in the area of sea west of these
islands. These islands do not constitute a part of Yemen's mainland coast.
Moreover, their barren and inhospitable nature and their position well out to
sea, which have already been described in the Award on Sovereignty, mean that
they should not be taken into consideration in computing the boundary line
between Yemen and Eritrea.
148.
For these reasons, the Tribunal has decided that both the single island of
al-Tayr and the island group of al-Zubayr should have no effect upon the median
line international boundary.
* * *
Base
Points on the Coast of Yemen
149.
Since Jabal al-Tayr and the Zubayr group are not to influence the drawing of
the median line boundary, it is necessary to decide upon the base points to be
used for this part of the coast of Yemen. For here again there is, if not a
carpet, at least a considerable scattering of islands and islets which are the
beginning of a large area of coastal islands and reefs which, extending
northward, ultimately form part of a large island cluster or system off the
coast of Saudi Arabia.
150.
There is also the relatively large, inhabited and important island of Kamaran
off this part of the Yemen coast. This island, together with the large
promontory of the mainland to the south of it, forms an important bay and there
can be no doubt that these features are integral to the coast of Yemen and part
of it and should therefore control the median line. One significant controlling
base point is therefore on the westernmost extremity of Kamaran. It seems
reasonable also to use as base points the very small islands immediately south
of Kamaran and west of the promontory headland mentioned above.
151.
The question remains as to the islands to the north of Kamaran. The relatively
large islet of Tiqfash, and the smaller islands of Kutama and Uqban further
west, all appear to be part of an intricate system of islands, islets and reefs
which guard this part of the coast. This is indeed, in the view of the
Tribunal, a "fringe system" of the kind contemplated by Article 7 of
the Convention, even though Yemen does not appear to have claimed it as such.
Indeed the Tribunal does not have the advantage of any views of Yemen about
this part of its coast because it chose to deploy its arguments differently. It
is however the view of the Tribunal that it is right to use as median line base
points not only Kamaran and its satellite islets which appear in the Yemen Map
12.1, but also the islets to the northwest named Uqban and Kutama.
152.
The above decisions having been made, it is now possible to compute and plot
the northern stretch of the boundary line between turning points 1 and 13 (the
list of the coordinates of the turning points is given below; see also the
illustrative Charts 3 and 4). For this entire part of the line, the boundary
should be a mainland-coastal median, or equidistance, line.
153. At
turning point number 13, however, a simple mainland/coastal median line
approaches the area of possible influence of the islands of the Zuqar-Hanish
group, and clearly some decisions have to be made as to how to deal with this
situation.
The
Middle Stretch of the Boundary Line
154.
It will be convenient for obvious reasons if the Tribunal first decides the
question of the boundary in the narrow seas between the south-west extremity of
the Hanish group on the one hand and the Eritrean islands of the Mohabbakahs,
High Island, the Haycocks and the South West Rocks on the other. In this part
of the boundary there is added to the boundary problem of delimiting
continental shelves and EEZ the question of delimiting an area of overlapping
territorial seas. This comes about because Zuqar and Hanish, attributed to the
sovereignty of Yemen, both generate territorial seas which overlap with those
generated by the Haycocks and South West Rocks, attributed to the sovereignty
of Eritrea. It would appear from Yemen Map 12.1 that Yemen assumed that Eritrea
is entitled only to a strictly 12 mile territorial sea extending from the
Eritrean base points chosen by Yemen along the high-water line on the Eritrean
coast; the outcome would be, according to Yemen, that the Haycocks and South
West Rocks are thus left isolated outside and beyond the Eritrean territorial
sea proper.
155.
This proposition is questionable, quite apart from the obvious impracticality
of establishing limited enclaves around islands and navigational hazards in the
immediate neighbourhood of a main international shipping lane. There is no
doubt that an island, however small, and even rocks provided they are indeed
islands proud of the water at high-tide, are capable of generating a
territorial sea of up to 12 miles (Article 121.2 of the Convention). It follows
that a chain of islands which are less than 24 miles apart can generate a
continuous band of territorial sea. This is the situation of the Eritrean islands
out to, and including, the South West Rocks.
156.
The point that the Yemen suggestion omits to take into account is that the
effect of what has been referred to as "leap-frogging" the Eritrean
islands and islets in this area is to extend the mainland coast territorial sea
beyond the limit of 12 miles from the mainland coast. According to Article 3 of
the Convention, the territorial sea extends "up to a limit not exceeding
12 nautical miles, measured from the baselines determined in accordance with this
Convention". This is permissible because each island, however small or
unimportant of itself, creates a further low-water baseline from which the
coastal territorial sea is to be measured. This "leap-frogging" point
was invoked strongly in support of Eritrea's claims to sovereignty. This
reasoning was not accepted by the Tribunal in its Award on Sovereignty, it
nonetheless has relevance in the present context.
157. If
any further reason were needed to reject the Yemen suggestion of enclaving the
Eritrean islands in this area beyond a limit of 12 miles from the high-water
line of the mainland coast, it may be found in the principle of
non-encroachment which was described by Judge Lachs in the Guinea/Guinea-Bissau
Award(15) in the following terms:
As stated in the award, our principal concern has been
to avoid, by one means or another, one of the Parties finding itself faced with
the exercise of rights, opposite to and in the immediate vicinity of its coast,
which might interfere with its right to development or put its security at risk.
158.
It will be seen that the international boundary line must therefore lie
somewhere in a belt of sea no more than four or five miles wide. Once it is
established that there is an area of Eritrean mainland coast territorial sea,
potentially extending beyond the South West Rocks and the Haycock group of
islands on the one hand and overlapping the territorial sea generated by the
Yemen islands of the Hanish group on the other, the situation suggests a median
line boundary. Under Article 15 of the Convention the normal methods for
drawing an equidistant median line could be varied if reason of historic title
or other special circumstance were to indicate otherwise. However, the Tribunal
has considered these reasons and circumstances and finds no variance necessary.
159.
Further bearing in mind its overall task of delimitation, the Tribunal also
finds this line to be an entirely equitable one. The decision of the Tribunal
is therefore that the median line is the international boundary line where it
cuts through the area of overlap of the respective territorial seas of the
Parties.
* * *
There
remains, however, the part of the boundary line which is to connect the
mainland coastal median line and the line delimiting the overlapping
territorial seas. To the description of this line the Award now turns.
The
Boundary Line Which Connects Turning Point 13 and Turning Point 15
160.
If the mainland coastal median were continued south of turning point 13, it
would cut first the territorial sea of Zuqar and then the territorial sea of
Hanish, and then cut through the land territory of the island of Hanish. It
must therefore divert to the west round the Zuqar-Hanish group, also respecting
the territorial seas of these islands if they are to be regarded as generating
a territorial sea. That they ought be regarded as having a territorial sea
seems reasonable.
161.
Various possibilities were considered by the Tribunal. If therefore the
international boundary is, after turning point 13 where it meets a 12 mile
territorial sea extending from the island of Zuqar, to be diverted in order to
respect that area of territorial sea, it could trace the sinuosities of the
Zuqar territorial sea boundary until it has to turn southward again in order to
join the Article 15 boundary. The Tribunal has decided, however, that it would
be better that the line here should be a geodetic line joining point 13 with
point 14, making the necessary southwestwards excursion to join the territorial
sea median line described above. Moreover, the Tribunal's task is, as mentioned
above, to determine the maritime boundary; this does not include setting the
limits of the territorial seas.
162.
From turning point 14, again with a simple line in view, the southward
excursion of the international boundary is a geodetic line joining points 14
and 15 where it becomes the Article 15 median. This boundary decided upon by
the Tribunal between turning points14 and 15 is also very near to the putative
boundary of a Yemen territorial sea in this area, but makes for a neater and
more convenient international boundary.
The
Southern Part of the International Boundary Line
163.
From turning point 20, which is the southernmost turning point on the
overlapping territorial seas median line, the boundary needs to turn generally
south-eastwards to rejoin the mainland coast median line. This it does through
a geodetic line which connects turning point 20 and point 21, the latter being
the intersection of the extended overlapping territorial seas median line and
the coastal median line. Thence the international boundary line resumes as a
median line controlled by the two mainland coasts. The Bay of Assab is internal
waters, so the controlling base points of the boundary line are seaward of this
bay.
The
Northern and Southern End Points of the Boundary Line
164.
Reference has been made above to the need not to extend the boundary to areas
that might involve third parties. The points where the decision of the Tribunal
halts the progress of the boundary line are, for the northern end, turning
point 1 and, for the southern end, point 29. The effect can, of course, also be
seen on the illustrative Charts 3 and 4 in the map section of the Award. The
Tribunal believes that these terminal points are well short of where the
boundary line might be disputed by any third State.
* * *
The
Test of Proportionality
165.
The principle of proportionality was described by the International Court of
Justice in the North Sea Continental Shelf cases as "the element
of a reasonable degree of proportionality, which a delimitation in accordance
with equitable principles ought to bring about between the extent of the
continental shelf areas appertaining to the coastal State and the length of the
coast measured in the general direction of the coastline, account being taken
for this purpose of the effects, actual or prospective, of any other
continental shelf delimitations between adjacent States in the same
region". This was also described as one of the "factors" to be
taken into account in delimitation.(16) It is not
an independent mode or principle of delimitation, but rather a test of the
equitableness of a delimitation arrived at by some other means.(17)
So, as the Award stated in the Anglo-French Channel case, "it is
disproportion rather than any general principle of proportionality which is the
relevant criterion or factor".(18)
166.
The Parties in the present case have disagreed strongly in their arguments of this
matter, not so much about the meaning of "proportionality" as over
the respective lengths of their coasts for the purposes of this calculation.
There is in the Tribunal's view no doubt that the "general direction"
of the coast means that the calculation of the Eritrean coastal length should
follow the outer circumference of the Dahlak group of islands, although Eritrea
was more inclined to have it follow the line of the mainland coast.
167. A
much debated point was: how far north the Eritrean coast should go. Eritrea
wished to include in the proportionality calculation the whole of its mainland
coast up to the latitudinal line of 16N; and, indeed, this line was used by
Yemen to define what it called its northern sector of the area in question. The
Tribunal however doubts the appropriateness of employing a horizontal line of
latitude to divide, for the purposes of the proportionality test, waters of the
Red Sea which lie at an angle of roughly 45. The Tribunal has therefore
considered the relevant proportion of the Eritrean coast, which can be said to
be "opposite" that of Yemen, as ceasing where the general direction
of that coast meets a line drawn from what seems to be the northern terminus of
the Yemen land frontier at right angles with the general direction of the Yemen
coast. In the same way the Tribunal determined the southern end point to be
considered for the computation of the length of the Yemen coast.
168.
The Tribunal through its expert in geodesy has calculated the ratio of the
lengths of the coasts concerned, measured by reference to their general
direction, and the ratio between the water areas it has attributed to the
Parties. The first ratio, of coastal lengths, Yemen : Eritrea, is 387026 metres
to 507110 metres, or 1 : 1.31. The second ratio of water areas,
including the territorial seas, Yemen : Eritrea, is 25535 kilometres2
to 27944 kilometres2, or 1 : 1.09. The Tribunal believes
that the line of delimitation it has decided upon results in no disproportion.
Notes
- Chapter V
13. ILM 1986, p. 251.
14. I.C.J. Reports 1969, p. 54.
15. See I.C.J. Reports 1981, p. 58, the Libya/Malta
case.
16. 18 ILM 60.