That's a job for the state governments. You don't need navy frigates for policing harbors any more than you need the SAS to patrol city streets for crime.
When John Howard stopped
just one boat with a naval vessel, before the 2001 elections (97% of the several 100 people in the boat checked out as legitimate refugees, so there were a grand total of maybe 10 people sent back to their home countries) it cost several million dollars a day, for weeks, to perform the operation. Yeah, but it "paid for itself" because the party got re-elected.
They're called 'unlawful non-citizens' by definition of the Migration Act. Seeking asylum is a lawful act when granted a visa. Entering the country without visa is not. Detention centers exist to separate the two.
That's just not correct: "Seeking asylum is a lawful act when granted a visa." is just wrong. Seeking asylum is a right of
any person who enters a country. Entering a country, no matter how you do it, and seeking asylum are two different things. You're not meant to enter the country unannounced, but once here, you have a
legal right to seek asylum. This is the sole reason John Howard started shipping people off to Nauru. As soon as they step on Australian soil, they have the
right under Australian Law to seek asylum, and have the claim properly processed.
Also, nobody is charged with a
crime for entering Australia's territory, are they? Crimes are defined as things you have to go to court for. Things a judge presides over. Since there is
no crime defined in the books for this, they're not criminals. Technically. But ...
"criminal" is 100% defined by the technicalities., not "I find that 'criminal' ". It's not a crime - according to the law - which is the sole arbiter of what is a "crime" in the first place.