Submarine Cable (Perth Protection Zone) Declaration 2007

The Declaration’s primary legal architecture rests on: (1) spatial delimitation; (2) nominal cable routing; (3) prohibition and restriction lists tied to specific gear and activities; (4) notification, consultation and consideration obligations directed to entities undertaking certain activities; and (5) technical thresholds intended to protect electro‑optic submerged plant items.

Spatial delimitation is explicit and granular. Section 6 defines the Perth Protection Zone by reference to a closed geodesic polygon whose vertices are set out in two coordinate tables and closed against the mean low‑water mark (s 6(a)-(d), tables 1 and 2). This provides a legally certain perimeter for operators, with coordinates expressed in WGS84 (s 6 note). The zone therefore has an onshore reference (mean low‑water mark) and extends seaward to specific latitudes and longitudes.

Nominal cable routing for the SEA‑ME‑WE3 cable is separately specified (s 7, table 3). The instrument distinguishes between the protection zone (the area) and a nominal location (the intended course of the cable within the zone), which matters because some restrictions and exceptions are framed against distances from the nominal position and proximity to submerged plant items (for example the 500‑metre crossing minimum in item 7(e)).

Prohibited and restricted activities are listed in tabular form. Table 4 (s 8) lists absolute prohibitions except for the limited exception in s 8(2) where similar gear used in bona fide fishing operations is treated as potentially allowed but subject to the detailed restrictions in table 5. Table 5 (s 9) organises the permissible but restricted activities into 17 items. Each item pairs an activity with a prescriptive restriction: technical equipment limits (breaking strain, weights, hook type), spatial constraints (not more than 500 metres from low‑water mark, or only in waters less than 100 metres deep), procedural requirements (21‑day notice to cable carriers, response to reasonable information requests within 7 days, consideration of representations), and performance duties (activity must not damage or impede the efficient operation, maintenance or repair of a submarine cable).

Definition work underpins the regime. The Declaration supplies a lengthy dictionary in s 3 (abalone spatula, anchor line, benthos, cable carrier, branching unit, branch line, dropping weights, equaliser, electro‑optic devices, and many more). Several defined concepts are functional‑technical (electro‑optic devices, equaliser, repeater, submerged plant items). The definition of cable carrier is conditional on whether the submarine cable is a network unit and whether a protection‑zone installation permit existed at installation (s 3 cable carrier). This means the identity of the notified party in many procedural obligations depends on the cable’s regulatory and ownership history.

Interaction with Schedule 3A to the Act is extensive and foundational. The Declaration is made under Schedule 3A, and several items cite or relate to numbered paragraphs of that Schedule (for example table 4 item 1 cross‑refers to subparagraph 10(4) of Schedule 3A; notes after table 5 reference paragraphs 11(3)(d)-(g) of Schedule 3A). The instrument therefore functions as a Schedule 3A localisation for the Perth area, fixing coordinates and operational rules required by that statutory framework.

Technical protection of electro‑optic equipment is explicit. Item 12(d) requires that planned seismic surveys be adjusted when pressure waves of 2.0 bar or more would arrive at electro‑optic devices, thereby setting an engineering threshold for one mode of seabed stress. Other rules , minimum crossing distances from submerged plant items (item 7(e)), constraints on anchor designs and breaking strains (item 17), and prohibited use of seabed‑contacting trawling and net types (s 8 table 4) , all work to reduce mechanical contact and shock risk to cables and associated equipment.

Procedural duties bind third parties who undertake infrastructure or seabed work in the zone. Items 7-14 typically require 21‑day advance notice to each cable carrier, prompt compliance with reasonable ACMA or cable‑carrier requests for information (within 7 days), and an obligation to consider and respond to representations regarding the likelihood of damage or impediment to cable operation, maintenance or repair. The Declaration therefore shifts information and communicative burdens onto private entities proposing activity, and gives cable carriers a formalised opportunity to be consulted.

Territorial and international law limits are acknowledged. Section 5 imposes the caveat that the Declaration applies only to the extent consistent with Australia’s jurisdiction under international law. That statement is a legal limit on unilateral application beyond territorial waters and clarifies the Declaration’s reach.

Collectively, these main concepts form a legalised, technical, notification‑centred protective regime for one submarine cable within a precisely defined maritime polygon.

The Declaration identifies three principal categories of actors. Each bears distinct legal burdens, rights to be notified, or constraints.

1. Cable carriers and related cable owners/operators. The instrument defines cable carrier in s 3 with a conditional test: the carrier depends on whether the submarine cable is a network unit, whether a protection zone installation permit was held at installation, or whether a carrier owns a network unit immediately connected to the cable. Cable carriers are the entities to whom procedural notices must be provided (items 7-14, table 5). Cable carriers receive information (particulars, location, expected commencement and duration) and may make reasonable requests for additional information, and submit representations about likely damage or impediments to efficient operation, maintenance or repair. The regime therefore grants cable carriers an active consultative role and procedural leverage over third‑party activities that may intersect with their asset.

2. Third‑party proponents of seabed or near‑seabed activities. This includes entities installing, maintaining or removing electricity cables or pipelines, entities constructing, maintaining or removing installations for ships, civil engineering contractors, companies conducting exploration for or exploitation of resources other than marine species, seismic survey operators, and research bodies conducting seabed contact research (items 7-14 of table 5). These actors face specific pre‑notification and engagement obligations: notably, giving each cable carrier particularised notice not later than 21 days before the activity (items 7-14), responding to reasonable written requests for information within 7 days, considering and responding to cable‑carrier representations, and ensuring activities do not damage or impede the efficient operation, maintenance or repair of submarine cables. For exploration and seismic surveys, there is an additional technical constraint for seismic operators to adjust grid lines where pressure waves of 2.0 bar or more would reach electro‑optic devices (item 12(d)).

3. Fishers, vessels and recreational mariners using lines, anchors or gear. The Declaration affects fishing and vessel operations through a combination of absolute prohibitions (s 8 table 4) and detailed restrictions (s 9 table 5). Certain gear is prohibited outright within the zone (s 8 table 4 item 2: mid‑water trawls, nets/ropes/chains capable of contacting seabed, demersal longlines, Danish and Scottish seines). But where fishing gear would otherwise be prohibited, an exception is made via s 8(2): if the activity is carried out in the course of fishing operations and is listed in items 1-5 of table 5 (restricted activities), then that gear is not automatically prohibited but must comply with the prescribed restrictions. Those restrictions include technical limits (e.g., breaking strain caps of 2.7 tonne for many lines, circle‑type hooks only, branch line limits of 500 kg, pot size and weight limits, dropper weight caps of 15 kg, hook‑type restrictions, and limits on J‑hook lines to 50 kg breaking strain) and spatial/depth limits (e.g., many activities must not occur in waters more than 500 metres from the low‑water mark unless other conditions are satisfied; some activities permitted in waters less than 100 metres deep). Vessel operators lowering, raising or suspending shotlines or anchors are similarly constrained by weight and breaking strain caps, types of permissible anchors and requirements for trip release mechanisms (items 16-17). The definition of “line” in s 4 clarifies that “line” uses ordinary meaning for fishing, shot lines and anchors, but the Declaration’s technical definitions for snood, mainline, branch line and trace specify how those instrument constraints apply.

Other affected parties appear by reference. The Declaration engages State and Commonwealth authorities to the extent that ocean disposal points and spoil grounds may be designated by Commonwealth or State governments (s 3 definitions). The definition of defence operation or practice, and defence practice area, ties some exceptions (e.g., explosives in item 15(c)) to the Defence Force Regulations 1952. Entities operating in or near navigational aids or installations for ships will also be affected due to the requirement to notify cable carriers and to ensure activity does not impede cable operations (items 9-10, 13).

Who pays and who decides. The instrument places the primary compliance costs and administrative burdens on third‑party proponents of activities and on users of fishing gear. They must adjust gear designs, observe weight and strain limits, give notices and respond to requests. Cable carriers incur the administrative task of receiving notifications and making representations if they consider an activity risky; they also gain a de facto procedural veto or at least the ability to seek mitigation because proponents must consider and respond to representations. ACMA, as the declaratory authority, is the deciding public body that made the instrument and whose powers under Schedule 3A provide the legal framework for enforcement, though specific enforcement mechanisms lie in that Schedule rather than in the Declaration text.

Behavioural effects. The Declaration will cause proponents of seabed‑contact activities to change planning and logistics: provide 21 days’ notice, design gear to comply with specified breaking strains and weights, avoid seabed contact beyond the covered distances where not expressly permitted, adjust seismic grid lines to protect electro‑optic devices, and choose anchor types with trip release mechanisms where operating beyond 500 metres from low‑water mark in permitted depths. Fishers will need to ensure their gear meets the construction and strength limits to operate beyond 500 metres from the low‑water mark. Cable carriers will be incentivised to monitor notifications and make representations where they perceive risk to their assets.

The instrument’s effects are spatially concentrated (around the SEA‑ME‑WE3 cable route and within the defined polygon) and functionally concentrated (on commercial fishing gear designs, seabed infrastructure proponents and seismic operators). The costs are diffuse across mariners and contractors who would otherwise use certain gear, but the procedural cost and mitigation obligations are concentrated on those who plan to undertake the restricted activities.

The Declaration creates a matrix of duties for proponents of restricted activities, rights for cable carriers, and prohibitions that give rise to duties of avoidance for users of particular gear. The key legal duties and rights derive from the specific tables and definition clauses.

Duties on third‑party proponents (items 7-14 and cross‑referenced items in table 5)

• Pre‑notification duty. Entities proposing to install, maintain or remove electricity cables or pipelines, to construct or remove installations for ships or navigational aids, to explore or exploit non‑marine resources, or to conduct research with seabed contact have a duty to provide each cable carrier with particulars of the activity, location, and expected commencement date and duration not later than 21 days before the activity (table 5 items 7-14, each contains paragraph (a)). This is a firm timeline and a precondition to lawful activity under the restricted item.
• Information cooperation duty. Proponents must comply with any reasonable written request for information from a cable carrier within 7 days (items 7-14, paragraph (b)(i)). The Declaration uses “reasonable” as a threshold for requests, but the timeframe is absolute.
• Consideration and response duty. Proponents must consider and respond to any reasonable representations made by cable carriers regarding likelihood of damage or impediment to efficient operation, maintenance or repair of submarine cables (items 7-14, paragraph (b)(ii)). The duty is procedural: proponents must consider and respond; the degree of substantive obligation to change plans is not spelled out within the Declaration beyond general “must not occur in a manner that damages or impedes” formulations (for example items 7(c), 8(c), 9(c), 10(c), 12(c), 13(c), 14(c)).
• Non‑damage performance duty. The activity must be carried out in a manner that does not damage, or is not likely to damage or impede, the efficient operation, maintenance or repair of submarine cables (items 7(c), 8(c), 9(c), 10(c), 12(c), 13(c), 14(c)). This duty sets a substantive standard, phrased as "does not damage" or "is not likely to damage", which places a risk‑based operational obligation on proponents.

Duties on fishers and vessel operators (items in table 5 and s 8)

• Gear and spatial limits. Fishers wishing to operate within the zone must ensure their gear meets the prescribed technical limits to fall within permitted exceptions. Examples: demersal gillnets may not be used more than 500 metres from low‑water unless conditions (depth <100m, breaking strain ≤2.7 tonne, no anchors or external weights, vertical retrieval) are met (item 1). Pots or traps beyond 500 metres must meet size and weight caps, mainline and branch line breaking strains, and prohibition against wire mainlines (item 2). Demersal droplines are limited to circle hooks, breaking strain caps, no wire mainline/snood/trace, branch line breaking strain limits and dropper weight caps (item 3). These are technical duties with measurable compliance thresholds.
• Anchor restrictions. Use of anchors and shotlines beyond 500 metres is subject to weight and breaking strain limits, trip release requirements, and permissible anchor types (item 17). Shotline lowering/raising restrictions are in item 16.
• Prohibition duty. Certain activities are absolutely prohibited (s 8 table 4), such as mid‑water trawls, demersal longlines, and nets which can contact the seabed. Prohibited activities must not be undertaken in the Perth Protection Zone unless the limited exception in s 8(2) applies.

Rights of cable carriers

• Right to be notified. Cable carriers are entitled to receive 21 days’ advance notice of specified activities (items 7-14).
• Right to request information. Cable carriers may make reasonable written requests for further information; the proponent must comply within 7 days (items 7-14).
• Right to make representations. Cable carriers may make reasonable representations about the likelihood of damage or impediment; the proponent must consider and respond to such representations (items 7-14).
• Implicit protective interest. While the Declaration does not create a property right in the text, the procedural and substantive duties give cable carriers a protective interest and an operational role in shaping third‑party activities that might affect their assets.

Duties on seismic operators

• Pressure wave threshold duty. If a planned seismic survey would result in pressure waves of 2.0 bar or more arriving at the seabed location of any electro‑optic devices associated with a submarine cable, the entity conducting the seismic survey must adjust the grid lines to reduce pressure at those devices to less than 2.0 bar (item 12(d)). This is a technical mitigation duty tied directly to the vulnerability of electro‑optic submerged plant items defined in s 3.

General and definitional duties

• Jurisdictional limitation. The Declaration applies only to the extent consistent with Australia’s international law jurisdiction (s 5), so entities and their advisers must confirm whether proposed activity falls within Australia’s jurisdiction before assuming the Declaration’s regimes apply.
• Definition‑based duties. Who is a cable carrier and which items qualify as submerged plant items or electro‑optic devices is determined by s 3 definitions; duties often attach to these defined terms and therefore hinge on how those definitions apply to the factual circumstances (s 3, examples included).

Absence of penalty specifics in the Declaration

• The Declaration does not set out enforcement mechanisms or penalties in its own text. Enforcement and sanctioning powers flow from Schedule 3A of the Telecommunications Act 1997, which is the sourcing instrument (cover sheet; cross‑references in tables). Parties must therefore consult Schedule 3A and the Act to determine the precise legal consequences of breaches.

Rights of other parties

• Defence and governmental exceptions. The use of explosives is permitted where it occurs in the course of a defence operation or practice conducted by or with the Australian Defence Force within a declared defence practice area (item 15(c)). Other governmental designations (ocean disposal points, spoil grounds) are recognised by definition (s 3) and may affect whether certain disposal activities are prohibited.

In sum, the Declaration creates a vertical information and procedural regime giving cable carriers notice rights and influence over third‑party activities, and imposes technical and spatial duties on fishers, vessel operators and infrastructure proponents to avoid mechanical damage or pressure harm to submarine cable equipment.

The Declaration itself does not contain an express schedule of penalties or a standalone enforcement chapter. It is an instrument made under subclause 4(1) of Schedule 3A to the Telecommunications Act 1997, and its prohibitions, restrictions and duties are framed to operate within that statutory architecture (cover sheet; s 1; multiple cross‑references to Schedule 3A provisions in tables 4 and 5 notes). Consequently the enforcement regime, available remedies, and sanctioning mechanisms governing contraventions will be those provided by Schedule 3A and the Act rather than by provisions of the Declaration text.

What the Declaration does make enforceable in practice

• Prohibitions. The activities listed as prohibited in table 4 (s 8) are given the legal character of forbidden conduct within the Perth Protection Zone subject to the jurisdictional caveat in s 5. That legal prohibition is an ingredient that Schedule 3A enforcement mechanisms will act upon, for example through civil or criminal penalties or injunctions as specified in the Act/Schedule 3A.
• Conditions precedent and procedural obligations. The 21‑day notice requirement and 7‑day response obligations are framed as conditions inherent in the restricted items (table 5, items 7-14). A failure to provide notice or to comply with reasonable requests could therefore constitute a contravention which Schedule 3A's enforcement provisions are intended to capture.
• Technical limits. The enumerated technical caps (breaking strains, weights, hook type) and the seismic 2.0 bar threshold are expressed as substantive constraints that, if not complied with, will be treated as contraventions under the statutory regime.

How to locate enforcement provisions

• The Declaration must be read together with Schedule 3A to the Telecommunications Act 1997 for the machinery of enforcement. The cover text of the instrument identifies the enabling provision (subclause 4(1) of Schedule 3A). Readers seeking the precise criminal or civil penalties, power of entry, remedial orders, administrative sanctions, or pecuniary penalties must therefore consult Schedule 3A and other relevant provisions of the Act. The Declaration’s own notes refer to specific paragraphs in Schedule 3A (for example table 5 notes reference paragraph 11(3)(d)-(g) and subparagraph 10(4)(a) in table 4 item 1).

ACMA’s role in enforcement and administration

• ACMA is the maker of the Declaration and is the statutory communications regulator defined in s 3. The ACMA will be the administering agency in practice for receiving notices, coordinating compliance and enforcing Schedule 3A powers, subject to the Act’s delegation and enforcement rules. The Declaration does not describe ACMA’s enforcement actions in this text but the authority to declare the zone and the procedural framing implies ACMA will be the focal regulator for compliance issues.

Practical enforcement consequences for operators

• Operational interruption. Non‑compliance could expose an operator to enforcement action that prevents the activity from commencing or continuing pending remediation, given the typical administrative remedy available to regulators in such frameworks.
• Cooperative compliance emphasis. The Declaration puts emphasis on notice, cooperation, and representations. The existence of these procedural duties indicates that much compliance will be addressed via pre‑activity engagement between proponents and cable carriers; enforcement action is likely to follow where parties neglect or refuse to engage, or where activities proceed despite representations asserting material risk.

Jurisdictional caveat

• Section 5’s limitation that the Declaration applies only to the extent consistent with Australia’s jurisdiction under international law is relevant to enforcement. If an activity occurs outside Australia’s maritime jurisdiction, enforcement under this Declaration/Schedule 3A will not be available.

Because the Declaration omits explicit penalty figures or enumerated enforcement powers, lawyers, compliance officers and contractors must cross‑refer to Schedule 3A and the Telecommunications Act 1997 to determine what fines, offences or remedial powers ACMA or other bodies may exercise in response to contraventions. The Declaration furnishes the conduct descriptions and procedural preconditions; Schedule 3A supplies the enforcement tools.

The Declaration is integrally connected to other statutory instruments and legal concepts. Its drafting repeatedly cross‑references Schedule 3A to the Telecommunications Act 1997 and imports meanings from other regulations.

Primary statutory linkage: Telecommunications Act 1997, Schedule 3A

• The Declaration is made under subclause 4(1) of Schedule 3A to the Telecommunications Act 1997 (cover sheet; s 1). Many of the prohibitions and restrictions reference clauses or subparagraphs of Schedule 3A (s 8 table 4 item 1; s 9 notes referencing paragraph 11(3) of Schedule 3A). Therefore, the substantive scope, enforcement powers and legal consequences of breaches must be read in conjunction with Schedule 3A. The Declaration functions as a localised application of Schedule 3A in a geospatial context.

Definitions imported from other instruments

• Defence terminology. The Declaration explicitly borrows meanings from the Defence Force Regulations 1952 for the terms defence operation or practice and defence practice area (s 3). This affects exceptions for the use of explosives (item 15(c), table 5) and indicates an interaction with defence law and designated defence practice areas.
• Geographic datums. Section 6 note states the co‑ordinates are provided in WGS84, identical to the Australian Geodetic Datum 1994 as described in Commonwealth Gazette GN35 (note). That ties the Declaration’s spatial descriptions to national geodetic standards and avoids ambiguity over coordinate systems.

Interaction with State law and other Commonwealth instruments

• Mean low‑water mark and coastline references use the coast of Western Australia and the State name Western Australia is defined (s 3). Ocean disposal points and spoil grounds are defined in s 3 to include points or areas designated by the Commonwealth or a State or Territory government. That indicates the Declaration accepts the continuing role of State and Commonwealth environmental, maritime and waste‑management regimes; for example an ocean disposal point designated by State law will operate within the Declaration’s definitions.
• Navigational aids and installations for ships may be subject also to marine safety legislation and port or harbour authorities’ rules. The Declaration does not displace such regimes but creates overlapping procedural obligations to cable carriers.

International law and maritime jurisdiction

• Section 5 limits the Declaration’s application to the extent consistent with Australia’s jurisdiction under international law. This draws a legal boundary around the Declaration’s reach in the maritime domain. Entities operating beyond Australia’s territorial sea or exclusive economic zone must assess whether the Declaration applies in particular circumstances.

Overlap with fisheries management and marine resource laws

• The Declaration regulates fishing gear types, design and allowable locations in ways that will intersect with fisheries management regimes under State or Commonwealth fisheries law. It does not replace fisheries licensing or quota systems but imposes additional gear and spatial constraints within the Perth Protection Zone. Fishers and fisheries managers must therefore ensure compliance with both the Declaration and fisheries legislation.

Environmental and exploration law

• For exploration and exploitation for resources other than marine species (item 12), proponents will need to take account of environmental law, petroleum or mining licensing, and other resource management statutes. The Declaration’s additional requirement , adjusting seismic grid lines where pressure exceeds 2.0 bar at electro‑optic devices , is a sector‑specific constraint that will sit alongside environmental impact assessment and resource licensing obligations.

Interaction with defence law

• The exception for explosives used in defence operations (item 15(c)) and the borrowing of definitions from the Defence Force Regulations 1952 indicate that defence activities authorised under defence law and within declared defence practice areas will not be impeded by the Declaration.

Administrative law and procedural fairness

• The Declaration sets up a process of notification and representations from cable carriers to proponents; such interactions may give rise to administrative law considerations (for example legitimate expectations, procedural fairness) depending on how ACMA or other public bodies exercise decision or enforcement powers under Schedule 3A. Although the Declaration itself does not create adjudicative processes, interactions between regulated parties and the regulator will occur within broader administrative law constraints.

In summary, the Declaration must be read and applied in concert with Schedule 3A of the Telecommunications Act 1997, the Defence Force Regulations 1952 for defence terms, State and Commonwealth marine, environmental and resource statutes, fisheries law, and international law limits on maritime jurisdiction. Practitioners must coordinate compliance across these intersecting regimes.

The Declaration’s own metadata and operative provisions record a narrow amendment history within the document itself.

• Date of instrument and commencement. The instrument is the Submarine Cable (Perth Protection Zone) Declaration 2007 made by the Australian Communications and Media Authority and dated 24 September 2007 (cover sheet), and it expressly commences on 1 February 2008 (s 2). The cover page shows the signatures of ACMA officials.

• No subsequent amendments recorded in this text. The Declaration as provided contains no schedules of amendment, no later dated variations, and no marginal notes indicating that the coordinates, tables, definitions or restrictions have been subsequently altered. The document’s content therefore reflects the 2007 Declaration as it stood at commencement on 1 February 2008.

• Cross‑reference to Schedule 3A of the Telecommunications Act 1997. The Declaration’s dependence on Schedule 3A for enabling authority means that any amendments to Schedule 3A after the date of this Declaration would affect how the Declaration operates. However, this instrument itself contains no internal amendment provisions or subsequent amending instruments attached.

Practical consequence for users

• To establish whether the Declaration has been subsequently amended, revoked or superseded, practitioners must check later ACMA instruments, the Federal Register of Legislation, and any legislative amendments to the Telecommunications Act 1997 (including Schedule 3A) that might alter the Declaration’s legal effect. The Declaration as supplied is a static snapshot without recorded later changes.

Because the Declaration provides coordinates and technical constraints, any future amendment could materially affect users (e.g., adjusting the protection polygon, changing permissible gear parameters, altering notification timeframes). As the Declaration in this text shows only the original 2007 drafting and the commencement date 1 February 2008, users should verify the current consolidated text before acting.

The provided Declaration does not include or reference any litigation or judicial consideration. It contains no footnotes, case citations, or references to judicial decisions. The text therefore records no litigation history within the instrument itself.

Legal practitioners seeking whether this Declaration has been the subject of judicial review, injunctions, prosecutions, or civil claims must search external sources , court databases, ACMA enforcement notices, and legal reporting databases , because the Declaration does not itself report or summarise litigation outcomes. The Declaration’s operative text focuses on definitions, coordinates, prohibitions and restrictions and makes no claim about existing judicial determinations.

Where parties have disputed applications of similar Schedule 3A protection zones in other contexts, those decisions would be relevant to interpreting procedural duties, the reasonableness of information requests and representations, and the standard applied to “likely to damage or impede the efficient operation, maintenance or repair” standard. However, no such materials are included in the Declaration provided here.

In the absence of litigation recorded in this instrument, users must treat the Declaration’s provisions as untested in the courts within the document’s own content. Any legal risk assessment should include independent research into subsequent cases or ACMA enforcement actions that may have interpreted or applied the Declaration or Schedule 3A powers in practice.

The Declaration contains a number of drafting features and operational details that can generate practical compliance traps if overlooked. Below are specific “gotchas” arising from the text.

1. Distinction between protection zone and nominal location

• The instrument makes a clear legal distinction between the Perth Protection Zone (s 6) and the nominal location of the SEA‑ME‑WE3 cable (s 7). Activities constrained by distance or proximity (for example the crossing distance in item 7(e)) refer to submerged plant items and their location, not merely the outer polygon. Proponents must therefore map both sets of coordinates when planning.

2. Multiple overlapping distance thresholds and depth conditions

• Several restrictions turn on whether an activity occurs “in waters more than 500 metres from the low‑water mark” (items 1-5, 11, 14-17) and whether the ship “is operating in waters less than 100 metres deep” (items 1 and 16-17). Operators must check both horizontal and vertical (depth) metrics. Failing to note the depth condition can incorrectly permit otherwise restricted operations.

3. Conditional exception in s 8(2)

• Section 8(2) saves paragraph 2(b) of table 4 (activity described in paragraph 2(b) , nets, ropes etc) from absolute prohibition if it is carried out in the course of fishing operations and is listed as a restricted activity in items 1 to 5 of table 5. Practically this means some gear that would be prohibited under table 4 can be used if the fisher complies with table 5 constraints. Failure to consult both tables may lead to mistaken assumptions of absolute prohibition.

4. Complex definition of cable carrier

• The definition of cable carrier in s 3 varies by the cable’s status: network unit, protection zone installation permit history, and ownership of adjacent network units. Determining who qualifies as “each cable carrier” to be notified may thus require investigation of historical permits and network unit status rather than a simple title search.

5. “Reasonable” requests and “considered and responded to” representations

• The Declaration requires proponents to “comply with any reasonable written request for information” from a cable carrier within 7 days (items 7-14) and to have “considered and responded to any reasonable representations” (same items). The terms “reasonable,” “considered” and “responded to” are discretionary and open to dispute. Practitioners should document all communications to avoid later challenges about sufficiency of response.

6. Multiple technical thresholds across items

• Breaking strain caps: 2.7 tonne appears repeatedly as the upper cap for many mainlines and droplines; branch line caps are 500 kg in multiple items; J‑hook demersal lines have a much lower cap of 50 kg (item 4). Trap dry weight caps and dropper weight caps are 15 kg. Shotline weight caps are 20 kg (item 16). Anchors have detailed weight and type constraints (item 17). These numbers must be applied precisely; mixing them up can result in non‑compliance.

7. Electro‑optic device vulnerability and seismic grid demands

• Item 12(d) requires seismic survey proponents to adjust grid lines if planned pressure waves of 2.0 bar or more would reach electro‑optic devices. That is an engineering mitigation obligation with potential operational cost if survey geometry must change. Operators must model pressure wave propagation with sufficient fidelity to detect whether the 2.0 bar threshold is at risk.

8. “Submerged plant items” definition and proximity rules

• The Declaration defines submerged plant items to include repeaters, equalisers and branching units (s 3 and example). Item 7(e) requires that new cables or pipelines do not approach or cross a submarine cable less than 500 metres from the submerged plant items of that cable “as determined following consultation with each cable carrier.” This makes the precise safe distance subject to consultation outcomes; proponents cannot rely solely on published coordinates but must engage with cable carriers to determine submerged plant item locations and acceptable crossing distances.

9. Jurisdictional boundary caveat in s 5

• The Declaration applies only to the extent consistent with Australia’s jurisdiction under international law. Parties should verify whether specific activities lie within Australia’s territorial sea or exclusive economic zone; otherwise, the Declaration’s prohibitions/restrictions may not apply. Reliance on the Declaration alone without maritime jurisdictional analysis is risky.

10. No enforcement detail in the Declaration text itself

• The Declaration sets obligations but does not enumerate penalties; enforcement must be sourced to Schedule 3A. Parties who ignore the Declaration may be exposed to enforcement action under the Act; conversely, the lack of penalty details in the instrument may complicate immediate assessment of legal exposure without consulting Schedule 3A.

11. Multiple cross‑referenced regimes

• Definitions import meanings from other instruments (Defence Force Regulations 1952; State designations for spoil grounds) and recognition of ocean disposal points by Commonwealth or State governments. Parties should not assume the Declaration displaces or supersedes other regulatory approvals or environmental licences.

12. Precision required in coordinates and datum

• The Declaration expressly states the coordinate system; an error in datum conversion or use of a different geodetic system can cause a misalignment in determining whether an activity falls within the protection zone. Practitioners must use WGS84 or the Australian Geodetic Datum 1994 equivalent.

These “gotchas” are operational and procedural; lawyers and compliance officers should incorporate them into checklists for project planning, vessel operations, seismic survey design, fisheries compliance and infrastructure deployment.

Complying with the Declaration requires a mixture of spatial due diligence, equipment specification checks, procedural notifications, engineering mitigation and record keeping. Below is a practical stepwise compliance blueprint grounded in the Declaration’s text.

1. Determine whether your activity falls inside the Perth Protection Zone

• Map the activity against the polygon in s 6 (tables 1 and 2) using WGS84 coordinates. Check whether the precise worksite is inside the polygon or lies on/near the mean low‑water mark described (s 6(a)-(d)). Use professional geospatial tools and the datum specified (WGS84).

2. Identify whether the activity is prohibited, restricted or outside the instrument

• Consult table 4 (s 8) to see if the planned activity is specifically prohibited. If it is an activity described in table 4 item 2, check s 8(2) to see if a fishing‑operation exception applies and then consult table 5 for the detailed restrictions.
• If the activity appears in table 5, identify the applicable item number and read the precise restrictions and exceptions (e.g., distance thresholds, breaking strains, anchor types, weights, hook types, depth conditions).

3. For restricted activities that require notification, provide 21 days’ notice

• Where items 7-14 or others require pre‑notification, provide each cable carrier with:
  • particulars of the activity to be undertaken,
  • the location of the activity,
  • the expected commencement date and the expected duration.
• The notice must be given no later than 21 days before the activity (items 7-14). Plan for lead times and internal approvals to ensure the deadline is met.

4. Identify and contact “each cable carrier”

• Using the cable carrier definition in s 3, determine who qualifies as a cable carrier for the SEA‑ME‑WE3 cable (owner, joint owner, nominated carrier declaration, protection zone installation permit holder, or owner of connected network units). Confirm contact details and preferred formats for notices and information exchange.

5. Be ready to respond to reasonable information requests within 7 days

• Expect that each cable carrier may make reasonable written requests for additional information. Prepare to comply within seven days (items 7-14). Build an internal tracking system to log requests and responses, and to ensure timelines are met.

6. Document consideration of representations and respond substantively

• If a cable carrier makes representations about likely damage or impediment, the proponent must consider and respond (items 7-14). Keep a written record of the representations, the internal assessment, and the substantive response explaining whether and how operational plans will be amended.

7. Ensure technical compliance with equipment and operational limits

• Apply relevant technical caps exactly: e.g., mainline breaking strains not exceeding 2.7 tonne, branch line limits of 500 kg, pot dry weight caps of 15 kg, dropper weight ≤15 kg, shotline weight ≤20 kg, demersal J‑hook lines ≤50 kg breaking strain, anchor types and weight limits in item 17, use of circle hooks for demersal droplines (item 3). If gear cannot meet caps, consider alternative gear or plan operations inside the 500 metre low‑water exclusion zone where allowed.

8. For seismic surveys, model pressure wave propagation

• If planning seismic surveys, calculate expected seabed pressure at the locations of electro‑optic devices associated with the cable. If pressure waves of 2.0 bar or more would arrive at those devices, adjust grid lines to reduce pressure seen by the electro‑optic devices to less than 2.0 bar (item 12(d)). Retain modelling evidence and correspondence with cable carriers about mitigations.

9. Avoid crossing submerged plant items closer than 500 metres

• For installing new cables or pipelines, minimise the path across the Perth Protection Zone (item 7(d)) and ensure the new cable, pipeline or equipment does not approach or cross an existing submarine cable less than 500 metres from submerged plant items (item 7(e)), with the location of submerged plant items to be ascertained following consultation with each cable carrier.

10. For fishing and vessel operations, implement gear‑modification programmes

• Update vessel gear inventories and procurement to ensure compliance with the technical caps and hook types. Train crew on retrieval practices (e.g., “fishing gear is retrieved vertically to the greatest extent practicable” in item 1(d)). Inspect anchors to confirm trip release mechanisms where required (item 17).

11. Respect the jurisdictional caveat

• Evaluate whether the work is within Australian jurisdiction; the Declaration only applies to the extent consistent with international law (s 5). Obtain marine jurisdictional confirmation from maritime authorities where necessary.

12. Recordkeeping and audit trail

• Keep copies of all notices, responses to information requests, internal assessments of representations, engineering reports (e.g., seismic pressure modelling), gear certification and maintenance records, and geospatial analyses. These documents provide evidence of compliance and reasonableness if ACMA enquiries or enforcement action follows.

13. Coordinate approvals with other regulatory regimes

• Ensure you have necessary licenses and permits from other authorities (fisheries, environmental, resource extraction, defence clearances where relevant, port authorities) because the Declaration does not displace those requirements. Provide cable carrier notices alongside applications where that will streamline coordinated approvals.

14. Engage early with cable carriers and maintain clear lines of communication

• Given the procedural emphasis on consultation, early engagement with cable carriers reduces the risk of late objections, costly redesigns, or enforcement conflict. Treat representations from cable carriers as material inputs to project design and safety management plans.

15. Seek legal and technical advice where definitions or thresholds are ambiguous

• The cable carrier definition and the phrase “reasonable” in relation to requests and representations can be subject to interpretation. Legal advice is warranted where there is disagreement over whether a request is reasonable, whether a representation was adequately considered, or the sufficiency of mitigation measures.

Following this blueprint will address the core documentary, technical and procedural duties the Declaration imposes. Because enforcement powers derive from Schedule 3A of the Telecommunications Act 1997, practitioners must also consult that Schedule to understand sanctions, penalties and ACMA’s enforcement tools in the event of non‑compliance.