At any one time, there are up to 19 massive bulk carriers being loaded in Port Hedland, the world's biggest iron ore port, in Western Australia's Pilbara region.
Their crew is a largely invisible workforce, but one that is vital for Australia's economy.
But unions have warned a global crew changing crisis amid the coronavirus pandemic is putting lives, and future trade, at risk.
"Without these seafarers, and they are small by number, but without them Australia's economy will collapse imminently," said Dean Summers, the national coordinator for the International Transport Workers Federation in Australia.
An estimated 300,000 seafarers around the world have not been able to leave ships and return when their contracts ended because of the COVID-19 pandemic.
Quarantine measures, and a lack of flights, have left many crew members at sea for up to 14 months.
"We know that seafarers are suffering terribly from mental health [issues], from isolation, from a desperate understanding that there's nowhere in the world that's going to guarantee their repatriation, even after being onboard their ships over a year without a single day off," Mr Summers said.
"It's dangerous and the resource sector should be aware.
"Seafarers [are] in control of ships that are fatigued, that are tired, that are worried about their families back home — and we hear daily that captains, chief engineers, senior officers on board are screaming out for help."
Taskforce urgently needed
The federation has called on the Federal Government to urgently set up a taskforce to facilitate crew changes across Australia, and allow seafarers to travel quickly and safely to and from seaports to airports; and to exempt seafarers from any caps on airport arrival numbers.
Some crew changes are happening, mostly in Queensland.
The Australian Maritime Safety Authority (AMSA) earlier this month briefly detained the Panama-registered bulk carrier, Grand Venture, in the Pilbara, until it could provide firm plans to repatriate long-serving crew.
Both AMSA and the Federal Transport Minister, Michael McCormack, declined an interview, but a spokesperson for the Minister said the government has been working with state governments, industry, port operators and unions to put arrangements in place enabling crew transfers to occur, while managing the risks of COVID-19 transmission.
The spokesman acknowledged that contract extensions could not continue indefinitely.
WA Ports Minister, Alannah MacTiernan, said shipping companies should be required to do the crew changeovers at the destination port, in Singapore or China, where there is better access to onward flights.
The State Government was working with industry to investigate charter flights, she said.
"These guys should not have been required to be onboard for nine or 12 months, and there's nothing in our rules making that a necessity," Minister MacTiernan said.
"It really has been to a significant extent cost-cutting and not being prepared to incur the additional expense that is necessary to replace these crews."
Shipping Australia said the WA Government needed to play its part to ensure crew changes could occur.
"It is the states that have been really stubborn and now I think WA is probably one of the worst in the country that is actually not allowing crew changes to occur," Shipping Australia deputy CEO Melwyn Noronha said.
"Shipping companies and shipping agents are bending over backwards to make these changes occur.
"Cost is not an impediment at the moment."
Calls to reinstate shore leave
John Hague runs the Port Hedland Seafarers Centre, which used to host some 30,000 international seafarers each year.
They contributed $5 million to the local economy when they would come ashore for a few hours and do some shopping.
But when COVID-19 struck, shore leave was one of the first things cancelled.
Mr Hague urged authorities to allow the seafarers to come ashore, even for just a few hours, in a temporary special quarantine zone at the centre.
"At least that would then give them a few hours off a ship to see other people, and talk to each other and just relax generally," he said.
"That would be a small breakthrough for us if that could take place."
Seafarers set up online shopping
Soon after the pandemic broke, the centre organised care packages for more than 300 ships as they entered port, full of cool drinks, sweets and SIM cards so the seafarers could call home.
It has now established an online shop, and makes daily deliveries out to the vessels.
"A happy crew is a safe crew, a safe crew is a safe ship, [and] safe ships ship good loads out of the country," Mr Hague said.
"For a ship to go array or people to break down and that supply chain to be broke, no iron ore goes out of this country.
"I don't think people realise how important seafarers are to this country."
