It depends
.
The reality seems to be that, as a non-European flagged vessel,
some officials in
some countries
may ask you for paperwork indicating your ability. In some ideas of "the" theory, your Australian state
license for driving a tinny (well, in
Queensland ) is enough because that is all your home-country rules require. Good luck
.
If you want to be slightly more careful, you could get an
ICC appropriate for your vessel type/size. This can still be questioned or ignored by locals, but is generally a lot more known than, say, a Tassie
fishing license . Note that sometimes getting the
ICC translated into the local language beforehand may help (can it hurt?!).
The RYA may have a leeeeetle influence, perhaps, if you can confidently wave one of their competencies (and probably plead in the local patois)...
If you really, really want to be sure, I'd approach the appropriate embassy in Oz and get an
email or letter advising that you're local competency has met the Australian standards. Letterhead is good.