High Tide Features in the SCS Arbitration: Distinguishing
small and insular land areas from seabed formations
CIL South China Sea Award Conference: The Legal Dimension
Session 4
Singapore, 5-6 January 2017
Youna Lyons, Centre for International Law
Outline
I. The Award
- Determined High Tide Features
- The Tribunal Reasoning
II. Which High Tide?
- Sea level Variation
- Different High Tides
III. Permanence Above the Sea
- Permanence Over Time and Temporary Islands
- Permanence in Same Location and Dynamic
Features
IV. Implications for Other Shallow Features
- Impact of new evidence and data
- Clear Cut vs. Dubious Cases
Introductory Comments
 Application of UNCLOS Article 121(1): What is a naturally formed area of
land above water at high tide?
 The Tribunal called it a ‘High Tide Feature’, the term used in this
presentation. A ‘High Tide Feature’ may be a simple ‘rock’ or a full fledge
‘island’ capable of generating an EEZ and continental shelf of its own
 Focus on the distinction between High-Tide Feature vs. Low Tide Feature
(whether a Low-Tide Elevation or a submerged feature; Not on the
distinction between Low Tide Elevation vs. fully submerged feature
 Which high tides can/should be used as reference?
 How often can a naturally formed area of land get submerged by naturally
occurring tide and forseeable meteorological processes whilst still
qualifying as an ‘island’ or ‘high tide feature’?
 Can a high tide feature be temporary, such that it exists for a few weeks
or a few months?
 Can it move places and still qualify as an above water area of land?
I. The Award
Determined High-Tide Features
In addition to Itu Aba, 10 features had their status determined:
High- Tide Features
Low-Tide Features
 Scarborough Reef
 Hughes Reef
 Cuarteron Reef
 Subi Reef
 Fiery Cross Reef
 Mischief Reef
 Johnson Reef
 Second Thomas Shoal
 McKennan Reef
 Gaven Reef North
I. The Award
1. Scarborough Reef
Determined High-Tide Features
3. Mc Kennan Reef and Gaven Reef North
Google Earth Digital Globe
23 Oct. 2014
Sea Level: +22cm
Above-water reef
formations mentioned in
some records
(‘reef boulders’ according
to the Tribunal) They appear to be
dynamic sand formations
in satellite imagery
0
Above-water rocks, up to 3-3.5m above
high tide, i.e. higher than the tidal range
2. Cuarteron Reef,
Fiery Cross Reef and
Johnson South Reef
Above-water rocks in some
records that are 1 to 1.5m high at
the most, i.e. smaller than the
tidal range
500m
I. The Award
The Tribunal’s Reasoning

No rule on any particular high-water vertical datum

States are free under the Convention to claim a high-tide feature or
island on the basis of any high-water datum that reasonably
corresponds to the ordinary meaning of the term “high tide”

Either Mean Higher High Water or Mean High Water Springs would be
an appropriate approximation of ‘high tide’

The tidal range in the SCS is comparatively small and the selection of a
vertical datum makes no substantial difference regarding the status of
the feature

Most convincing evidence concerning the status of the SCS features is to
be found in nautical charts, records of surveys and sailing directions
I. The Award
The Tribunal’s Reasoning
 Rocks and large coral boulders cemented to the platform of a reef have a
high degree of permanence and can reasonably be expected to remain
largely unchanged, even over centuries. Older direct observations are
thus not per se less valuable, provided they are clear in content and
obtained from a reliable source
 Ephemeral features such as sand cays pose a greater challenge but can
also be consistent over time and will often reform in the same location if
dispersed by a storm
 In the context of this case, as for all sensitive determinations, the
depiction of features on published maps is often not sufficient and it is
beneficial to have recourse to original survey data, prepared by
individuals with direct experience and knowledge of the area in question.
I. The Award
Permanence over time
Two Issues of Permanence Above the Sea
 High tide level: How many times a month
can it be submerged whilst still qualifying
as above water at high tide?
 Can it be temporary? E.g. ephemeral sand
formations, effect of sea level rise (20cm
in the last century), active erosion/traces
of seawater infiltrations
Permanence in same
location
 Dynamic sand banks: appear, disappear,
re-appear in different locations, with
different shapes and sizes
II. Which High Tide?
 X
Tide and Sea Level Variation
24 hours
TIDE ≡ Astronomic Tide
SURGE ≡ Wind-induced Surge
hours
spring
neap
TOTAL ≡ TIDE + SURGE
spring
TIDAL AMPLITUDE
neap
SURGE Height
1 month
days
January
days
1 year (2011)
II. Which High Tide?
Tide and Sea Level Variation
Highest Astronomical Tide
Highest Tide of the Year
High Spring Tide
Mean High Water Spring
Mean Higher High Water
High Neap Tide
Hourly Sea Level
Mean Sea Level
Low Neap Tide
Mean Lower Low Water
Low Spring Tide
Mean Low Water Spring
Lowest Tide of the Year
Lowest Astronomical Tide
II. Which High Tide?
Sea Level Variation
Sea Level Variation across the South China Sea
Prepared for this conference by Pavel Tkalich and Luu Quang Hung, Physical Oceanography Lab of TMSI, National University of Singapore
II. Which High Tide?

Case Law
The Tribunal decided to rely primarily on historical surveys and, in
doing so, departed from the view of the Court in the Nicaragua vs
Columbia case on the basis that it ‘must be understood in the context
of that case’

The Tribunal favoured any historical evidence that suggested that a
feature would have been above high tide during the observation
period, be it 2 weeks or less

By contrast, in Nicaragua vs. Columbia, the court indicated to be taking
a cautious view of what feature may qualify as a High Tide Feature as
‘even the smallest island generates a 12-nautical-mile territorial sea’; it
‘has to make sure that it has before it evidence sufficient to satisfy that
a maritime feature meets the test of being above water at high tide’.
II. Which High Tide?
Case Law – Lessons Learned

The solution adopted in Nicaragua vs. Columbia and in the SCS
Arbitration are so different that that they can only be explained by
the facts of each case and the evidence presented to the judges

In both cases, the judges were limited by available evidence; new
scientific data on sea level variations in the South China Sea would
therefore help the determination of the status of still undetermined features
III. Permanency Above Sea Level
Over Time
Does a temporary above-water land formation qualify as an
‘island’ or ‘high tide feature’?

Fast sea level rise of around 20cm per century over low lying when
not subsiding geographic formations

Dynamic sand banks and cays which appear and disappear under the
combined effects of astronomic tides, storm surges and wind-waves
and rarely if ever reappear in the same location with the same shape
and size

Natural erosion of these low-lying formations as evidenced by
seawater infiltration processes visible on several high resolution
satellite images of the SCS above-water features.
III. Permanency Above Sea Level
Over Time

The SCS Award recalls that according to the Travaux Préparatoires of
Article 121(3), the word ‘island’ covers all portions of territory
permanently above water in normal circumstances (and capable of use or
habitation)

However, the Tribunal refers to the ‘high degree of permanence’ of ‘rocks
and large coral boulders cemented to the platform’ only to justify the
reliability of old record of direct observations of such type of features;
There is no discussion of permanence of High Tide Feature

The Tribunal finds that ephemeral features ‘can be consistent over time’
(…) ‘a sand cay may be dispersed by storm action and reform in the same
location after a short while. The absence of a sand cay at a particular point
in time is thus not conclusive evidence of the absence of a high-tide
feature’
III. Permanency Above Sea Level
Over Time
 However, none of the High Tide Features determined by the Tribunal is
characterized as a ‘recurring’ sand cay. Each of them is characterized as a
‘rock’ or a ‘boulder’
 In Nicaragua vs. Columbia, the Court found that the fact that a High Tide
Feature is composed of coral debris is irrelevant as ‘international law defines
an island by reference to whether it is “naturally formed” and whether it is
above water at high tide, not by reference to its geological composition’.
According to the Court, what mattered was the photographic evidence
which showed that the feature was ‘composed of solid material, attached to
the substrate, and not of loose debris.’
 Publicly available satellite imagery suggests that some ‘boulders’ may be
ephemeral formations that are dynamic, under the combined effect of
astronomic tides, storm surges and wind-waves and do not generally reform in the same location
III. Permanency Above Sea Level
Over Time: Mc Kennan Reef
WorlView-1
18 Jan 2012
Sea Level: -4cm
Google Earth
2 Feb 2004
Sea Level: -6cm
Google Earth
10 March 2015
Sea Level: +34cm
Google Earth
26 Feb 2014
Sea Level: +6cm
III. Permanency Above Sea Level
Mc Kennan Reef
III. Permanency Above Sea Level
Ikonos-2 True Colour
2 Nov 2008
Sea Level: -37cm
CRISP 2008
WorlView-1 True Colour
17 Nov 2010
Digital Globe
In Same Location: Gaven Reef North
Google Earth
17 Dec 2012
Sea Level: -34cm
Google Earth
23 Oct 2014
Sea Level: +22cm
Google Earth
10 March 2015
Sea Level: +34cm
Google Earth
24 July 2016
III. Permanency Above Sea Level
Gaven Reef North
III. Permanency Above Sea Level
In the Same Location: Sandy Cay
22 April 2005
Sea Level: +12cm
Google Earth
5 March 2014
Sea Level: +32cm
Google Earth
16 April 2014
Sea Level: +44cm
Google Earth
GeoEye-1 True Colour
28 Feb 2015
Sea Level: +11cm
DigitalGlobe 2015
III. Permanency Above Sea Level
Sandy Cay
IV. Implication for Other Shallow
Five Categories of Features
Features
Out of around 120 disputed shallow geographic features in the SCS:
1. Eleven features determined by the Tribunal
2. Largest features covered by terrestrial vegetation (not just mangrove) such
as Itu Aba, Thitu Island, Spratly Island, West York, Sand Cay, Sin Cowe,
Northeast Cay, Southwest Cay and Nanshan island
3. Features consistently found to be fully submerged or exposed at low tide
only, such as Macclesfield Bank, Most of Reed Bank, Most of Ardasier Bank,
Lys and trident Shoals, Vanguard Bank, Alexandra Bank, Prince Consort and
Prince of Wales Banks.
4. Features consistently found to have above water high tide parts in sailing
directions and nautical charts (and not determined by the Tribunal)
5. Dubious cases, whether due to the non-conclusive nature of the sailing
directions, the presence of dynamic sand banks, the absence of any
terrestrial vegetation, evidence of seawater infiltrations, questionable
above-water formations prior to island building constructions.
IV. Implication for Other Shallow Features
Flat Island
Vietnam
Bamford Reef
Collins Reef
Edmond Reef
Empire Reef
Gent Reef
Grierson Reef
Hallet Reef
Higgens Reef
Holiday Reef
Hughes Reef
Johnson South Reef
Jones Reef
Loveless Reef
McKennan Reef
Ross Reef
Sin Cowe Island
Tetley Reef
Unnamed Reef 1
Whitsun Reef
Eastern Reefs
Meiju Reefs
Thitu Island
Sandy Cay
Lamkiam Cay
Loaita Cay and
Loaita Nan
Loaita Island
Kugui Reefs
Menzies Reef
Eldad Reef
Gaven Reefs
Itu Aba
Namyit Island
Petley Reef
Sin Cowe Island
Sand Cay
Zhongzhou Reef
North Reef
Northeast Cay
South Reef
Southwest Cay
North Danger Reef
Lys Shoal and Trident Shoal
Nares Bank
Brown, Leslie, Templer
and Wood Banks
West York Island
Thitu Reefs
Subi Reef
Hopkins Reef
Irving Reef
Tizard Bank
Hopps Reef
Western Reef
Jackson Atoll
Livock Reef
Southern Bank
Hardy Reef
Discovery Great Reef
Discovery Small Reef
Second Thomas Shoal
Boxall Reef
Alicia Annie Reef
First Thomas Shoal
Maralie Reef
Central Reef
West Reef
Alison Reef
Barque Canada Reef
Prince of Wales Bank
Rifleman Bank
EEZ boundary (disputed)
Mariveles Reef
Ardasier Reef
Dallas Reef
Ardasier Bank
Swallow Reef
Vanguard Bank
Extended continental shelf
(claimed)
Continental shelf or extended
continental shelf boundary
(claimed)
Investigator Shoal
Amboyna Cay
Grainger Bank
Bombay Reef
Kingston Shoal
Johnson Patches
Orleana Shoal
12 NM arc around confirmed
High Tide Features in Award
12 NM arc around likely
High Tide Features
12 NM arc around possible
High Tide Features
High Sea
Deane Reef
Dickinson Reef
Hampson Reef
Hoare Reef
Petch Reef
Commodore Reef
Erica Reef
Alexandra Bank
Legend
Half Moon Shoal
Cornwallis South Reef
Spratly Island
Prince Consort Bank
Royal Captain Shoal
Pigeon Reef
East Reef
Ladd Reef
Royal Charlotte Reef
Erjiao Reef
Langkou Reef
Xiantou Reef
Louisa Reef
North Luconia Shoals
Seahorse Breakers
Herald Reef
Luconia Breakers
Stigant Reef
Malaysia
Hayes Reef
South Luconia Shoals
Comus Shoal
Bombay Shoal
Investigator Northeast Shoal
Pearson Reef
Cuarteron Reef
Foulerton Reef
Pennsylvania South
Reef
Sao Bank
Sabina Shoal
Mischief Reef
Union Reefs
Seahorse Shoal
Iroquois and Baker Reefs
Nanshan Island
Loaita Bank
Fiery Cross Reef
Amy Douglas Bank
Marie Louise Reef
North Reef
Pennsylvania North Reef
Reed Tablemount
Brunei Darussalam
Philippines
IV. Implication for Other Shallow Features
Flat Island
Vietnam
Bamford Reef
Collins Reef
Edmond Reef
Empire Reef
Gent Reef
Grierson Reef
Hallet Reef
Higgens Reef
Holiday Reef
Hughes Reef
Johnson South Reef
Jones Reef
Loveless Reef
McKennan Reef
Ross Reef
Sin Cowe Island
Tetley Reef
Unnamed Reef 1
Whitsun Reef
North Reef
Northeast Cay
South Reef
Southwest Cay
Eastern Reefs
Meiju Reefs
Thitu Island
Sandy Cay
Lamkiam Cay
Loaita Cay and
Loaita Nan
Loaita Island
Kugui Reefs
Menzies Reef
Eldad Reef
Gaven Reefs
Itu Aba
Namyit Island
Petley Reef
Sin Cowe Island
Sand Cay
Zhongzhou Reef
Lys Shoal and Trident Shoal
Nares Bank
North Danger Reef
Brown, Leslie, Templer
and Wood Banks
West York Island
Thitu Reefs
Hopkins Reef
Subi Reef
Irving Reef
Nanshan Island
Loaita Bank
Tizard Bank
Southern Bank
Livock Reef
Discovery Great Reef
Hardy Reef
Discovery Small Reef
Mischief Reef
Union Reefs
Fiery Cross Reef
Maralie Reef
Prince Consort Bank
Barque Canada Reef
Royal Captain Shoal
Half Moon Shoal
Deane Reef
Dickinson Reef
Hampson Reef
Hoare Reef
Petch Reef
Commodore Reef
Erica Reef
Alexandra Bank
Amboyna Cay
Mariveles Reef
Ardasier Reef
Dallas Reef
Investigator Shoal
Ardasier Bank
Rifleman Bank
Vanguard Bank
Swallow Reef
Bombay Reef
Kingston Shoal
Johnson Patches
Orleana Shoal
Legend
12 NM arc around confirmed
High Tide Features in Award
12 NM arc around likely
High Tide Features
12 NM arc around possible
High Tide Features
High Sea
EEZ boundary (disputed)
Pigeon Reef
Royal Charlotte Reef
Erjiao Reef
Langkou Reef
Xiantou Reef
Louisa Reef
North Luconia Shoals
Seahorse Breakers
Hayes Reef
Herald Reef
Luconia Breakers
Stigant Reef
South Luconia Shoals
Comus Shoal
Bombay Shoal
Investigator Northeast Shoal
Cornwallis South Reef
Spratly Island
Grainger Bank
Extended continental shelf
(claimed)
Continental shelf or extended
continental shelf boundary
(claimed)
Alison Reef
East Reef
Prince of Wales Bank
Boxall Reef
First Thomas Shoal
Pearson Reef
Foulerton Reef
Pennsylvania South
Reef
Sao Bank
Sabina Shoal
Second Thomas Shoal
Alicia Annie Reef
Ladd Reef
Seahorse Shoal
Iroquois and
Baker Reefs
Hopps Reef Jackson Atoll
Western Reef
Central Reef
Cuarteron Reef
West Reef
Amy Douglas Bank
Marie Louise Reef
North Reef
Pennsylvania North Reef
Reed Tablemount
Malaysia
Brunei Darussalam
Philippines
Conclusion

Over 100 shallow geographic features that are in dispute in the South
China Sea have not been the subject of a status determination in the
Award

Methodology with respect to the identification of geographic features
which are above water at high tide and therefore capable of
appropriation is based on the evidence available to the Tribunal and
cannot be transposed to new evidence and scientific facts

If small above-water rocks cannot be determined with certainty solely
on the basis of satellite imagery, historical observations can be placed
back into historiography of sea level variations based on satellite
altimetry data

Sand Cays are dynamic in the South China Sea and their movement can
be monitored with certainty in satellite imagery
Questions?
[email protected]
Source: Census of Marine Life:
http://www.comlmaps.org/extra/ngs/Ocean_Life_Diversity_Distribution-300dpi.pdf
Thank you!