reached via preservation of the “character as high seas of the waters above the
continental shelf and the right to their free and unimpeded navigation are in no way
thus affected”. Hence, the Proclamation did not alter the limits of the territorial
waters of the US, making it clear that the expansion of jurisdiction obeyed a
functional-economic purpose: the conservation and prudent utilization of natural
resources of the continental shelf.
Noticeable in that document was the clear-cut distinction between seabed and
superjacent waters, as the Proclamation does not extend coastal state powers to the
water column above the shelf, so as not to threaten freedoms of navigation. To make
this distinction even clearer, President Truman published another proclamation on
fisheries, instead of treating it within the instrument on the continental shelf, in other
to pinpoint the difference between seabed and water column. Interestingly, the
Proclamation established exclusive resource jurisdiction to the US, but does not
determine the breadth of the continental shelf under national jurisdiction. The Press
Release of the Proclamation suggests the adoption of a depth criterion to assess the
continental shelf under US jurisdiction, in line with which “submerged land which is
contiguous to the continent and which is covered by no more than 100 fathoms
(600 feet) of water is considered as the continental shelf”. That would imply,
roughly, 182 meters deep.
Following the 1945 Proclamation, several developing states in Central and South
America welcomed wholeheartedly the measure and, in their turn, made own
unilateral declarations based on the US documents. A detailed list of countries
forwarding such claims is provided in Chap. 4, in the scope of the analysis of the
“rise of coastal states” and the practice of creeping jurisdiction both before and after
the adoption of UNCLOS. For now, it suffices to highlight that a plethora of
unilateral jurisdictional claims succeeded, varying in nature, some of them without
a single reference to the expression “continental shelf”,
46 a phenomenon that led to
the need to clarify the limits of coastal State’s jurisdiction over maritime zones off
their shores.
Thus, after the move by the US President, there was considerable inconsistency
on the extent and nature of continental shelf claims by coastal states—some claimed
jurisdiction, some claimed sovereignty. The need to place limits on clearly extensive
continental shelf claims has triggered the work of the International Law Commission
(ILC), which adopted the first draft articles on the continental shelf by 1951.
47 A
final version of those draft articles was adopted in 1956, one that combined two
criteria for limiting the continental shelf: water depth and exploitability.
48 The draft
articles served as the basis for the 1958 Geneva Convention on the Continental Shelf
(CSC), which defined continental shelf as the submarine areas adjacent to the coast
(but outside the territorial sea) up to a depth of 200 meters or to a depth where
46 For an early critique on the phenomenon of jurisdictional claims, see Lauterpacht (1950), p. 376.
47 International Law Commission, Memorandum on the Regime of the High Seas, A/CN.4/32, 1950.
48 Report of the International Law Commission, 8th Session, A/CN.4/102/Add.1, II YB ILC, 1956,
at 251.
2.3 Definition of Continental Shelf Within and Beyond 200 nm
31
continental shelf and the right to their free and unimpeded navigation are in no way
thus affected”. Hence, the Proclamation did not alter the limits of the territorial
waters of the US, making it clear that the expansion of jurisdiction obeyed a
functional-economic purpose: the conservation and prudent utilization of natural
resources of the continental shelf.
Noticeable in that document was the clear-cut distinction between seabed and
superjacent waters, as the Proclamation does not extend coastal state powers to the
water column above the shelf, so as not to threaten freedoms of navigation. To make
this distinction even clearer, President Truman published another proclamation on
fisheries, instead of treating it within the instrument on the continental shelf, in other
to pinpoint the difference between seabed and water column. Interestingly, the
Proclamation established exclusive resource jurisdiction to the US, but does not
determine the breadth of the continental shelf under national jurisdiction. The Press
Release of the Proclamation suggests the adoption of a depth criterion to assess the
continental shelf under US jurisdiction, in line with which “submerged land which is
contiguous to the continent and which is covered by no more than 100 fathoms
(600 feet) of water is considered as the continental shelf”. That would imply,
roughly, 182 meters deep.
Following the 1945 Proclamation, several developing states in Central and South
America welcomed wholeheartedly the measure and, in their turn, made own
unilateral declarations based on the US documents. A detailed list of countries
forwarding such claims is provided in Chap. 4, in the scope of the analysis of the
“rise of coastal states” and the practice of creeping jurisdiction both before and after
the adoption of UNCLOS. For now, it suffices to highlight that a plethora of
unilateral jurisdictional claims succeeded, varying in nature, some of them without
a single reference to the expression “continental shelf”,
46 a phenomenon that led to
the need to clarify the limits of coastal State’s jurisdiction over maritime zones off
their shores.
Thus, after the move by the US President, there was considerable inconsistency
on the extent and nature of continental shelf claims by coastal states—some claimed
jurisdiction, some claimed sovereignty. The need to place limits on clearly extensive
continental shelf claims has triggered the work of the International Law Commission
(ILC), which adopted the first draft articles on the continental shelf by 1951.
47 A
final version of those draft articles was adopted in 1956, one that combined two
criteria for limiting the continental shelf: water depth and exploitability.
48 The draft
articles served as the basis for the 1958 Geneva Convention on the Continental Shelf
(CSC), which defined continental shelf as the submarine areas adjacent to the coast
(but outside the territorial sea) up to a depth of 200 meters or to a depth where
46 For an early critique on the phenomenon of jurisdictional claims, see Lauterpacht (1950), p. 376.
47 International Law Commission, Memorandum on the Regime of the High Seas, A/CN.4/32, 1950.
48 Report of the International Law Commission, 8th Session, A/CN.4/102/Add.1, II YB ILC, 1956,
at 251.
2.3 Definition of Continental Shelf Within and Beyond 200 nm
31