Ruling the waves – regulating Australia’s offshore waters

Robyn Briese 
Senior General Counsel 
T 02 6253 7569
Sacha Moran 
Senior General Counsel 
T 02 6253 7403

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Ruling the waves – regulating Australia’s offshore waters
Legal briefing 116 1 December 2020
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– some examples of special international law zones and the modification of 
UNCLOS jurisdiction by treaty.
• the powers of the Commonwealth, the states and the Northern Territory to make 
laws that apply to offshore areas, including:
– extraterritorial legislative power
– the Offshore Constitutional Settlement (OCS) 
• the principles and general legislative schemes relevant to determining whether 
domestic laws, including both the common law and statute, apply in an offshore area.
We also provide a checklist of issues to assist Commonwealth agencies that are 
developing legislation that will need to apply in Australia’s offshore areas.
The relationship between the international law of the 
sea and domestic laws
The international law of the sea governs issues such as the sovereignty and sovereign 
rights of nations
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over areas of the sea, the freedoms of ships to traverse the seas, 
a range of freedoms to engage in other activities in maritime areas, and maritime 
jurisdiction. A first attempt by nations to codify the law of the sea resulted in the 
adoption of several treaties under the auspices of the United Nations in 1958.
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In 1982 a new treaty – UNCLOS – was adopted. UNCLOS entered into force in 1994, 
replacing the previous UN conventions.
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Australia has ratified UNCLOS, although some 
other nations have not and remain bound by the 1958 conventions and the customary 
international law of the sea (this includes the United States of America, for example).
At the core of UNCLOS is the recognition of: 
• a coastal nation’s sovereignty extending beyond its land and internal waters over
‘an adjacent belt of sea’, described as the territorial sea (UNCLOS, Art 2)
• the allocation of certain sovereign rights to a coastal nation in respect of a belt of 
sea and sea floor extending beyond the territorial sea, described as the EEZ and the 
continental shelf (UNCLOS, Arts 55 and 76) 
• the allocation of rights to non-coastal nations to undertake certain activities in 
waters subject to the sovereignty or sovereign rights of a coastal nation (UNCLOS, 
Arts 17, 58 and 78)
• the freedom of the high seas (UNCLOS, Art 87).
This recognition forms the basis for Australia’s authority to legislate in these areas as 
a matter of international law. As a matter of domestic law, these international rules 
do not directly affect the power of the Commonwealth or the states to make laws with 
respect to offshore areas (which is discussed further below). Nonetheless, several of 
the concepts developed in Commonwealth legislation have arisen from implementing 
international law rules. In particular, the provisions of the Seas and Submerged Lands 
Act 1973 (Cth) (the SSL Act) declare that Australia’s sovereignty and sovereign rights 
2 To avoid confusion, in this briefing we use the word ‘nation’ to refer to an entity that constitutes a ‘State’ in the international law 
sense (for example, the United Kingdom), and the word ‘state’ to refer to the Australian states and the Northern Territory.
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These were the Convention on the Territorial Sea and the Contiguous Zone, the Convention on the High Seas, the Convention 
on Fishing and Conservation of the Living Resources of the High Seas, the Convention on the Continental Shelf and the Optional 
Protocol of Signature concerning the Compulsory Settlement of Disputes arising out of the Law of the Sea Conventions of 29 April 
1958 (Geneva) (all of which share the Australian Treaties Series reference [1963] ATS 12).
4 Paragraph 1 of Art 311 of UNCLOS provides that ‘This Convention shall prevail, as between States Parties, over the Geneva 
Conventions on the Law of the Sea of 29 April 1958’.

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Ruling the waves – regulating Australia’s offshore waters
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according to the maritime zones established under UNCLOS are vested in the Crown in 
right of the Commonwealth. Accordingly, it is useful to refer to these international law 
rules in order to provide context to the SSL Act and other domestic laws. 
Importantly though, even where an Australian law 
operates inconsistently with international law rules, it 
will remain valid and enforceable in Australian courts.