Folks,
The whole history of how expat Australians, and seamen in particular have been taxed over the years is a very interesting one, the rot really set in with the Whitlam government in 1972.
Prior to that, seamen only paid tax on that proportion of their income gained in Australian territorial waters --- ie; if they were in the international trade, they paid almost no tax.
The Whitlam era also severely changed the definitions of an Australian resident for tax purposes, and also introduced the "principle" that Australian expats, if they ever wanted to return to live in Australia, had to pay the greater of Australian income tax or the resident tax where they were domiciled.
The definitions of an Australian resident for tax purposes ( which does not mean simple residence in Australia) has been fiddled around by successive governments --- on the advice of the ATO, many times, never to the benefit of the taxpayer ---- unless you are on the government payroll ---- have a look at wonderful tax deals for the mob working for AusAid.
What is proposed for seamen looks like it is very close to the expat (but not seamen) tax situation before Whitlam.
Any expat must take very careful tax advice, to not do so can cause quite extraordinary tax bills, as some ex-RAAF pilots working for the Sultan of Oman's air force, found out in the most distressing way. when they returned to Australia.
Unfortunately, no Liberal/National government ever saw fit to reverse this particular ratbag tax increase by the Whitlam government.
What should also be looked at is the changes the government is making to the depreciation treatment of Australian flagged shipping. Internationally uncompetitive depreciation rate is a cost impost on Qantas that significantly adds to Qantas costs, vis a vie most of the international competition.
Folks, start lobbying hard for Australian aircraft to be treated the same way as Australian shipping, where Albo realized Australian shipping could never be competitive with Australia's tax structure --- so it was changed!!
Tootle pip!!