Welcome aboard. Congratz on your sail to Australia
I am no expert, but it is my understanding that you don't have to do much paperwork, but that most of the onus will be on the new owners.
However, it is my understanding that either you, or, more likely, the purchaser will have to pay the following taxes
2. Goods & Services Tax (GST)
GST is 10% of the value of the boat (usually the sale
Duty is 5%, but that will include the value of the boat and also the cost of getting the boat to Australia (which is assessed at the discretion of Australian Customs
, not based on your actual costs).
It all seems to me to be a bit of a minefield, but I reckon your best bet would be to sell the boat as an American boat and make it clear to any prospective buyer that this is the case, and let the buyer worry about satisfying the GST and duty requirements.