Law of the Sea – Baselines, Bay Closing Lines & Related Issues

Opening karakia and congratulations for arriving at 08:30.
A class representative is required; volunteer to see lecturer after class.
Printing the UNCLOS booklet:
• Commercial supplier quote: 38\text{ NZD} to print; Campus Books surcharge 30\text{ NZD} → total 68\text{ NZD} (deemed excessive).
• Local printer (Bond Street Printers) estimate: 25–30\text{ NZD} per copy if printed in bulk; cost rises for single copies.
• Two options: (1) students self-print at Warehouse Stationery, etc., or (2) lecturer orders bulk copies and sells for cash (25–30\text{ NZD} depending on volume).
• Vote taken; majority prefer lecturer-supplied copies. Possible Wednesday delivery if order placed today.
• Clarification: booklet is the full Law of the Sea Convention, not a substitute for prescribed textbook.
Online quizzes: mandatory minimum of eight is dropped. Now optional; best five scores × 2\% each → 10\% of course grade. Doing fewer than five forfeits remaining marks.

Straight baselines (UNCLOS Art. 7) permitted where:
• Coast is “deeply indented” or fringed with islands.
• Lines must not depart from general direction of coast.
• Waters landward must be closely linked as internal waters; economic interests may be considered.
Bay closing lines (Art. 10) introduced; today’s focus is detailed application & practice.

Baseline = point from which every other maritime zone is measured (territorial sea, contiguous zone, EEZ, continental shelf).
Waters landward of a closing line or straight baseline become internal waters → full sovereignty, no right of innocent passage (subject to limited historical exceptions).

Motivation: convert entire bay to internal waters.
Two-step legal test:
a. Semicircle Test:
• Identify natural entrance points of bay.
• Draw a straight line (diameter) across the entrance.
• Construct semicircle outward with radius r = \tfrac{1}{2}\text{(length of diameter)}.
• If area of water behind the diameter exceeds area of semicircle \bigl(A_{\text{water}} > \tfrac{1}{2}\pi r^{2}\bigr), the bay qualifies.
b. Length Limit: diameter must not exceed 24\text{ nautical miles (nm)}.
If diameter > 24\,\text{nm}, state must “step in” to a shorter chord that still meets semicircle test.

Mouths of Rivers (Art. 9): line may be drawn between low-water marks at river mouth; no length limit.
Ports (Art. 11): baseline may follow outer permanent harbour works.
Low-Tide Elevations (Art. 13):
• Feature above water at low tide but submerged at high tide.
• May serve as a base point only if it lies within 12\,\text{nm} of the mainland or an island.
Islands (Art. 121): every naturally formed land area above water at high tide generates its own full set of maritime zones unless it is a rock “which cannot sustain human habitation or economic life,” in which case only a territorial sea is generated.
Historic Bays (Art. 10 §6): long-standing state practice may override semicircle rule; treated as internal waters by historic title.
Artificial Islands / Installations (Art. 60 & 80): cannot be used as base points; only natural features count.

Identify natural entrance points.
Draw straight line (candidate diameter).
Use compass/divider to draw semicircle outward.
Compare areas qualitatively or, if data available, quantitatively.
Verify diameter ≤ 24\,\text{nm}.
If test fails, either:
• Shorten diameter (new entrance points), or
• Revert to straight baselines (Art. 7) or normal baselines (Art. 5).

Multiple candidate entrances; all diameters large.
Semicircle covers very wide offshore area; water area behind candidate lines smaller → fails test.
Straight baseline argument rejected: island distribution not “fringing” and orientation would depart from general coastal direction.
Default: normal baselines following low-water line; individual islands can generate their own territorial seas/EEZs.

Entrance ambiguous; any plausible chord likely > 24\,\text{nm} and semicircle dominates.
Conclusion: cannot be closed; revert to normal baselines.

Students found viable chord from prominent “nub” to Coromandel headland: \approx 22.7\,\text{nm} (< 24).
Semicircle area ≪ water area; qualifies.
Alternative longer chord (Leigh–Coromandel) measured >24\,\text{nm} and would fail length test.

Diagram shown: presence of a low-tide elevation close to State A shifts median line markedly seaward, enlarging State A’s EEZ/continental shelf claim.
Strategic importance explains why states negotiated Art. 13 compromise.

Nautical charts (hydrographic office) provide low-water line; ordinary tourist maps usually do not.
Mariners still need to consult tide tables and notices to mariners for real-time hazards.
Compass/semi-circle tools useful for field planning; digital GIS now common, but exam will not require physical protractor.

Question raised: why is the USA not a party despite “consensus” adoption?
• Consensus did not mean unanimity; developed states, esp. US, objected to Part XI seabed-mining & tech-transfer rules.
• 1994 Implementing Agreement modified Part XI; US still unsigned but follows many provisions as customary law.

Expansive baseline claims maximise sovereign control but can encroach on navigational freedoms, fishing rights, or neighbouring states’ entitlements.
UNCLOS tries to balance coastal-state interests and international navigation; misuse (e.g. excessive straight baselines) risks dispute and undermines legal certainty.

Bring cash on Wednesday if purchasing printed convention.
Quizzes: attempt as many as you like; top five count.
No geometry instruments required in graded assessments, but understanding methodology is examinable.

Be able to describe and apply semicircle test including formula A = \tfrac{1}{2}\pi r^{2}.
Know 24\,\text{nm} limit and absence of maximum for straight baselines.
Distinguish between straight baselines, bay closing lines, and normal baselines.
Explain rules for low-tide elevations and ports.
Recognise strategic/legal relevance of historic bays and artificial structures.
Understand administrative logistics: importance of possessing full UNCLOS text during first six weeks and test.