My understanding of maritime law is that any boarding of a free, law abiding vessel on the high seas, in international waters, is an act of piracy. Where do we or anyone else get the right to board and tow a vessel anywhere?

Back on the boats?
Close observers of what is taking place ii politics on this subject.
Not what is rumbling around in their heads.
Will have seen opposition said it would continue Rudd,s latest plan if they win.
Thinkers may consider all the negativity from the sides is, contributing to the boats still coming.
We are not just a single country web page, we have had many international contributors.
Maybe even more just dropping in for a look.
I believe both side,s now support stop the boats take no arrivals.
But probably based on a past mistake, a view seen here that every thing the government does is not supported has some thinking our resolve is weak.

What has Abbott actually come up with that is going to benefit AU.
Everything he has said is in the negative, not one word of advancement.
He somehow has got Howard stuck between the fragments of his brain. Costello nailed him when he said, Abbott is an economic illiterate, this has got to run true. He has not even mentioned the word.
How can anyone put trust in a person like that. PNG is being accepted and will soon see their first arrival of patrons.
Tent city on a tropical island will be very suitable for voluntarily dislodged persons. There will be no more luxury liners transporting people to AU.

Chrisgraff;
The master of the vessel has committed a crime in Indonesia by making an illegal
departure not being cleared from a port, carrying paying passengers on an unsurveyed
vessel, intending to carry undocumented persons into a foreign counntry etc etc etc.

Is that enough for starrters ?

Bazz,
Yes, true, but back in Indonesia. Once he is in international waters he is not subject to the home laws until he arrives back. He may well be in breach of the destination laws although judging by our court decisions and based on the penalties applied it seems that it is a bit like the Truancy Act. It is there but we no longer enforce it.

Chris,

I think under international law, you can only interfere with a vessel (outside of assistance when in difficulty) if you have the sanction of the country where the vessel is registered.

So if Indonesia sanctioned Australian interference of its registered vessels in international waters, that would be okay (?).

But Indonesia doesn't appear to be about to give that sanction.