Ruling the waves – regulating Australia’s offshore waters

Where the sea starts – internal waters
International law
Waters on the landward side of the baseline are described as ‘internal waters’ (UNCLOS, 
Art 8). UNCLOS recognises that a coastal nation has sovereignty over its internal waters 
(UNCLOS, Art 2, para 1). 
Foreign vessels generally have no right of navigation through internal waters. An 
exception to this general principle is the ‘right of innocent passage’ over some internal 
waters. Under Art 8 of UNCLOS, when a straight baseline is established, which ‘has the 
effect of enclosing as internal water areas which had not previously been considered as 
such’, there is a right of innocent passage in those internal waters. The right of innocent 
passage is discussed in more detail below. 
8 Rocks which cannot sustain human habitation or economic life of their own have a territorial sea and contiguous zone but do not 
have an EEZ or continental shelf (UNCLOS, Art 121).
‘...the ‘normal baseline’ is 
the low water line along 
the coast as marked on 
large-scale charts officially 
recognised by the coastal 
nation.’

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Ruling the waves – regulating Australia’s offshore waters
5
Australian law
Section 10 of the SSL Act describes the internal waters of Australia as any waters of the 
sea on the landward side of the baseline of the territorial sea. This section declares that 
sovereignty vests in and is exercisable by the Crown in right of the Commonwealth in 
respect of:
• the internal waters, so far as they extend from time to time
• the airspace over the internal waters
• the seabed and subsoil beneath the internal waters.
However, the Commonwealth and the states have entered into an arrangement about 
jurisdiction over Australian waters known as the Offshore Constitutional Settlement, 
which is discussed further below. Relevantly, that arrangement gives the states 
non-exclusive jurisdiction over internal waters, over the first 3 nautical miles of the 
territorial sea, and in the ‘adjacent area in respect of the State’: see Coastal Waters (State 
Powers) Act 1980 (Cth) s 5.