Seas and Submerged Lands Act 1973

The Act directly affects the constitutional balance between the Commonwealth and the States, offshore resource companies, commercial fishers, shipping operators, marine scientists, environmental regulators, and Australia’s neighbours, particularly Timor-Leste.

The Commonwealth is the primary beneficiary: ss.6, 10, 10A and 11 vest sovereignty and sovereign rights in the Crown in right of the Commonwealth. All federal departments and agencies exercising maritime jurisdiction—Defence, Home Affairs, Resources, Environment, and the Australian Fisheries Management Authority—rely on these declarations.

States and the Northern Territory are affected in two opposing ways. On the one hand, s.14 and the detailed qualifications in s.16(2) preserve their historic internal waters and, where proprietary rights have been vested by Commonwealth law, their ability to legislate in respect of the seabed. On the other hand, the general rule in s.16(1)(b) prevents State laws from purporting to exercise sovereignty or sovereign rights over the territorial sea or continental shelf in a manner inconsistent with the Commonwealth’s declarations. The Greater Sunrise provisions in s.13AB(1) go further: they disapply State and Territory laws in that area unless a contrary intention appears.

Private parties holding interests in offshore petroleum, greenhouse-gas storage, or fishing concessions are regulated by the rights declared in the Act. The joint-exercise obligation in s.13AA and the law-disapplication rule in s.13AB mean that title, environmental approvals, and safety regulation for Greater Sunrise projects must be pursued through the treaty institutions rather than ordinary Commonwealth or State legislation.

International actors are affected because the Act’s limits must be consistent with UNCLOS and relevant treaties. Timor-Leste is expressly given joint rights in the Greater Sunrise special regime area; the cessation mechanism in s.13AC ties the domestic regime to the life of the Treaty. Charts prepared under ss.9, 10C, 13 and 13C constitute prima facie evidence in any domestic court and are therefore relevant to diplomatic negotiations and potential dispute settlement under UNCLOS Part XV.

The Act is largely declaratory rather than prescriptive, yet it creates or confirms several important rights and a limited set of duties.

Rights vested in the Commonwealth:

• Sovereignty over the territorial sea, airspace, bed and subsoil (s.6) and over internal waters (s.10).
• Rights and jurisdiction in the exclusive economic zone (s.10A), including the sovereign rights described in the preamble (exploration, exploitation, conservation and management of natural resources, production of energy from water, currents and winds, jurisdiction over artificial islands, marine scientific research and marine environmental protection).
• Sovereign rights over the continental shelf for exploration and exploitation of natural resources (s.11).
• Rights of control in the contiguous zone for the prevention and punishment of infringements of customs, fiscal, immigration and sanitary laws (preamble and s.13A).

The Governor-General’s powers to declare limits by Proclamation (ss.7, 10B, 12, 13B) and to declare historic bays and waters (s.8) are expressed as discretionary but must stay within the bounds of the cited UNCLOS articles and any relevant international agreement.

The Minister’s power to prepare and certify charts (ss.9, 10C, 13, 13C) carries an evidentiary right: production of a certified copy is prima facie evidence of the matters shown.

In the Greater Sunrise special regime area, Australia’s Article 77 rights must be exercised jointly with Timor-Leste (s.13AA). The note to that section indicates that the treaty institutions may perform that function. The correlative right is the ability to rely on s.13AB(1) to disapply otherwise applicable laws, subject to contrary intention.

Duties are few but significant. The Minister must, by notifiable instrument, announce the day on which the Greater Sunrise Special Regime ceases (s.13AC(2)). All Proclamations and charts must remain consistent with UNCLOS and relevant treaties. The savings provisions in ss.14–16 impose an implicit duty on Commonwealth agencies not to disturb historic State waters or to claim ownership of physical infrastructure listed in s.15.

The Act itself contains no offence-creating provisions or direct penalties. Enforcement occurs indirectly through the laws whose operation is saved or excluded by the Act.

Because sovereignty over the territorial sea and internal waters is vested in the Commonwealth, federal statutes such as the Crimes Act 1914, the Customs Act 1901, the Fisheries Management Act 1991 and the Environment Protection and Biodiversity Conservation Act 1999 can apply to activities within those waters. The rights of control in the contiguous zone (s.13A) are exercisable under those same statutes to prevent or punish infringements inside Australia or the territorial sea.

In the Greater Sunrise special regime area, the blanket disapplication in s.13AB(1) means that the ordinary enforcement machinery of Commonwealth, State and Territory law is switched off for matters connected with exploration or exploitation of the continental shelf unless a particular statute expresses a contrary intention. Enforcement therefore depends on the treaty mechanisms and any specific Commonwealth law that carves itself back in.

Breach of the limit-declaration discipline (for example, a Proclamation that exceeds the breadth permitted by UNCLOS) would be justiciable as an excess of power, but the Act does not prescribe a statutory penalty; relief would be by way of judicial review.

The Act is expressly designed to sit atop a pyramid of Commonwealth, State and international instruments.

At the international level, s.3(1) incorporates the definitions from UNCLOS Parts II, V and VI (set out in Schedule 1). Every Proclamation power is conditioned on consistency with the cited articles and “any relevant international agreement”. The Timor Sea Maritime Boundaries Treaty is given direct domestic effect through the definitions in s.3(1), the joint-exercise rule in s.13AA, the disapplication rule in s.13AB and the cessation trigger in s.13AC.

Domestically, the Coastal Waters (State Powers) Act 1980 and the Coastal Waters (Northern Territory Powers) Act 1980 are expressly referenced in s.16(2)(b) as the source of State legislative power over the seabed once proprietary rights have been vested by Commonwealth law. The Offshore Petroleum and Greenhouse Gas Storage Act 2006 is engaged by the note to s.13AA; title and regulatory functions in the Greater Sunrise area flow through the treaty institutions created under that Act as amended.

Section 16(1) is a non-obstante clause that preserves the operation of all other Commonwealth and Territory laws and limits the extent to which State laws can contradict the vesting of sovereignty. The two limbs of s.16(2) ensure that State laws dealing with resources where proprietary title has been transferred, or laws otherwise within the powers conferred by the Coastal Waters Acts, are not read down.

The Seas and Submerged Lands Act therefore operates as a constitutional and interpretive overlay: it does not itself regulate conduct but determines which sovereign entity possesses the underlying title and rights that other statutes then regulate.

The text reflects amendments made after Australia ratified UNCLOS in 1994 and after the conclusion of the 2018 Timor Sea Maritime Boundaries Treaty.

The insertion of Division 1A (exclusive economic zone) and Division 2A (contiguous zone), together with the new subsections in s.3 and the corresponding proclamation powers (ss.10B, 13B), aligned the Act with the 1982 Convention after its entry into force. The “from time to time” wording in ss.3(2A), (3A) and the new proclamation rules allow the limits to move with evolving State practice and international agreements without fresh primary legislation.

The addition of Division 2AA and the detailed Schedule 2 coordinate table implement the 2018 Treaty. The joint-exercise obligation (s.13AA), the law-disapplication rule (s.13AB) and the automatic cessation provision (s.13AC) were required because the Treaty creates a temporary special regime for the Greater Sunrise gas field that straddles the new maritime boundary. The 2019 note in s.3(1) referring to the AustLII Australian Treaties Library is a practical updating measure.

These changes were driven by the need to maintain consistency with Australia’s international obligations, to resolve the long-running Timor Sea boundary dispute, and to provide regulatory certainty for the joint petroleum development that is expected to generate significant government revenue for both countries.

The source text does not record specific litigation, but the structure of the Act reveals the controversies it was designed to quell and those it may still generate.

The preamble recites the pre-existing sovereignty over the territorial sea and the sovereign rights over the continental shelf; this language mirrors the declarations that were challenged in the early 1970s when several States contested the Commonwealth’s authority to legislate beyond the low-water mark. The savings provisions in ss.14–16 represent a legislative settlement of that federal–State tension: historic State waters are preserved, proprietary rights vested by Commonwealth law are respected, and State legislative capacity conferred by the Coastal Waters Acts is saved.

The Greater Sunrise provisions introduce a new layer of controversy. Section 13AB(1) disapplies State and Territory laws in the special regime area. A State seeking to apply its environmental or royalty legislation to activities in that area would have to persuade a court that the particular statute reveals a “contrary intention” within the meaning of s.13AB(2). The interaction between that disapplication and the treaty institutions referenced in the note to s.13AA is likely to generate disputes about whether a particular regulatory decision is an exercise of “Australia’s rights” under Article 77 that must be taken jointly.

The prima-facie-evidence status of ministerial charts (ss.9(3), 10C(2), 13(2), 13C(2)) could be contested where a chart is said to depart from the coordinates in Schedule 2 or from the baseline rules in the Convention. Because the Act ties the charts to the Proclamation powers, judicial review would focus on whether the Proclamation itself complied with the “not inconsistently with” constraint.

The cessation mechanism in s.13AC raises a justiciable question of when the Greater Sunrise Special Regime “ceases to be in force under the treaty”. The Minister’s notifiable instrument is the statutory trigger; any party affected by the sudden re-application of ordinary Australian law after cessation could challenge the Minister’s identification of the date.

Most practitioners assume that once a Proclamation has been made under s.7 or s.12 the limits are fixed forever; in fact ss.3(2)–(5A) provide that references to each zone are to the zone “so far as it extends from time to time”, so a new Proclamation or a change in the baseline (for example by reason of sea-level rise or coastal accretion) automatically updates the legal boundary without fresh legislation.

The Greater Sunrise special regime area is defined by 18 precise points in Schedule 2 using GDA94 coordinates. Because the position on the surface of the Earth must be determined by reference to that datum (cl.1(2) of Schedule 2), any GPS or mapping software using a different datum (such as WGS84) will produce a mismatch of several metres—enough to move a wellhead in or out of the joint regime.

Section 13AB(1) is a blanket disapplication of “a law of the Commonwealth, a State or a Territory” for anything “directly or indirectly connected with” exploration or exploitation of the continental shelf in the area. The phrase “indirectly connected” is extraordinarily broad; a State workplace-health-and-safety prosecution of a contractor supplying catering services to a rig could be caught. The only escape is to locate an express “contrary intention” in the statute being invoked.

The savings in s.16(2)(a) turn on whether “proprietary rights in respect of that sea-bed or subsoil have become vested in the Crown in right of the State … by or under a law of the Commonwealth”. Many State petroleum titles were issued under mirror legislation after the Offshore Constitutional Settlement; whether those titles satisfy the vesting condition is not always obvious and has never been judicially tested in the current statutory language.

Finally, the evidentiary status of charts is only prima facie. In a contested boundary hearing, a well-resourced litigant can lead expert hydrographic evidence to rebut the chart, forcing the Commonwealth to fall back on the underlying Proclamation and its consistency with UNCLOS.

Compliance begins with due diligence on which maritime zone any proposed activity falls within. Obtain the most recent Proclamations under ss.7, 10B, 12 and 13B and overlay them on the certified charts issued under ss.9, 10C, 13 and 13C; these charts are prima facie evidence, so they should be the starting point for any mapping exercise.

For activities in the Greater Sunrise special regime area, compliance requires engagement with the treaty institutions rather than ordinary regulatory pathways. Any exploration or exploitation title must be sought through the Designated Authority or Governance Board. Legal advice should identify whether the proposed activity is “directly or indirectly connected with” the continental shelf; if so, ordinary Commonwealth, State or Territory approvals are prima facie disapplied unless the authorising statute expressly applies notwithstanding s.13AB.

Resource companies should maintain a register of the exact coordinates in Schedule 2 and ensure that all GIS layers use the GDA94 datum. A deviation of even one second of arc can place a drill site outside the joint regime and into an area where standard Australian title and environmental laws suddenly apply.

Commonwealth agencies must ensure that any new legislation intended to operate in the special regime area expressly states a contrary intention under s.13AB(2). Failure to do so will leave a regulatory gap that cannot be cured by policy or subordinate instruments.

States and the Northern Territory should review their offshore legislation to confirm that it falls within the carve-outs in s.16(2); if a law purports to assert sovereignty over the territorial sea or continental shelf outside those carve-outs, it risks being read down under s.16(1)(b).

Finally, because the zones “extend from time to time”, compliance is not a one-off exercise. Annual checks against new Proclamations, updated charts, and the status of the Timor Sea Maritime Boundaries Treaty are prudent. When the Minister publishes a notifiable instrument under s.13AC(2), all regulatory arrangements for Greater Sunrise must be revisited on the day after the Special Regime ends.