5% duty + 10% GST based on the fair market value of the yacht (as determined by a local yacht broker).
Best to use a customs broker (might even be mandatory). The FMV that the yacht broker comes up with (which will be at the very low end) should help keep the import costs down.
Some costs of getting the boat to Oz can be deducted before the duty is calculated.
Quarantine will demand that the yacht is fumigated (unless there is no wood whatsoever in the construction). This might cost anywhere from AUD1$k to AUD$3k depending upon the size (hope you don't have wooden spars).
Not an Aussie but the answer is that on importing the boat you pay the 10% GST (VAT) based on a local valuation from a valuer. That even if you are an immigrant (NZ has a policy of allowing immigrants to enter their boats free of tax). I understand the valuations tend to be considerate but do include the extraordinary costs of getting the boat there. You have to ask any questions of the customs at the expected port of entry (well until recently that was so), not customs head office. Some ports are regarded as being kinder in the treatment than others with respect to the valuation and maybe an Oz can give some current info on that. Friends I have known who have entered their boats permanently there have tended to get them looking a bit rundown before arrival to help with the valuation aspect.
You do not have to import the boat until the period of temporary entry expires (12 month I think) OR when you start employment in Australia but if you have to declare yourself as an immigrant ie not an Australian or NZ citizen, then I would expect that the tax will have to be paid upon your arrival. If that poses a difficulty, in many cases of extended temporary stays customs will accept a bond from a trusted bondholder (bank, or whathaveyou) - they may also do that for an immigrant and would be worth checking.
As always, the real advice has to come from Australian customs. While it is quite some years since I have had any direct discussion with them, I found them extremely helpful - that was the Brisbane office.
I was told a few months ago by an Oz who had recently imported a boat that the 5% duty was no more (like you I was under the impression it still existed) - maybe worth a double check by snowleopard.
Maybe my friend was just plain lucky then, so Snowleopard may have to add another 5% to the bill. I had come across the 5% with a few commercial vessels bought here by Oz's and imported into Australia - perhaps in some ports they turn a bit of a blind eye for pleasure boats? I was recently talking to a friend who intends moving to Australia later this year with his boat and after his investigations he was also under the impression that he only had the 10% to pay now. Obviously something worth double checking before any commitment.
I think also, and did not put this in my post, it is still that if the boat is less than 12 months old then it is the purchase price that is used, not a valuation.
Not as bad as it was before GST came in a few years ago though, when it was around 23% sales tax plus another around 23% duty as well (except for NZ'ers who just had to pay the sales tax).
We have thought about moving across a number of times but I think I would end up choking on my coffee too, because as sure as hell the moment we paid the tax the rules would change so NZ'ers or other immigrants were exempted and we would already have waved the money goodbye!
swmbo is more likely to swallow a one-way trip than the full circumnavigation and, being a wimp, i'm not wild about the choice of facing pirates or the southern ocean to get round africa!
Aah ! Now I understand. But if you did sell it down under and fly back would you be mad enough to build another - or would you become pragmatic and buy - or really unhappy and do without ?
<hr width=100% size=1>a pragmatist is an optimist with a boat in the UK