Seven new COVID-19 cases reported in Queensland have come from a gas tanker off the Sunshine Coast.
The state recorded nine cases overnight, with the other two detected in hotel quarantine.
It's possible more cases will come from the British-flagged Inge Kosan in coming days, and Deputy Premier Steven Miles said the government was deciding whether patients would be treated on board or taken ashore.
"Queensland Health is very good at this, they work with Maritime Safety Queensland and with the ship to ensure testing occurs, to ensure that health services are provided, and they'll be making decisions about where best to provide those health services," Mr Miles said on Wednesday.
Consideration is being given as to whether infected patients can be quarantined on the vessel to reduce risk to the rest of the crew.
Mr Miles said healthcare had been provided on board ships in similar cases.
The Maritime Union is also calling for an independent investigation into the death of a crew member whose body washed up on a beach in Vanuatu two weeks ago.
"There are serious questions that must be answered about how the deceased seafarer died, and how his body came to be washed up on a beach in Vanuatu," MUA national secretary Paddy Crumlin said.
"Now that the vessel is anchored in Australian waters, local authorities have the opportunity and obligation to launch a thorough, independent investigation."
There were similar calls in Vanuatu for a thorough investigation into why the body of the middle-aged Filipino crew member was in the sea and how he died.
"There is no question that the circumstances are highly suspicious," Vanuatu-based Canadian journalist Dan McGarry told AAP.
Meanwhile an audit investigating the fit testing of personal protective equipment in Queensland hospitals "revealed widespread inconsistencies and deficiencies", according to the Queensland Nurses and Midwives Union.
"The data has clearly demonstrated what the QNMU has long feared, that there are huge inconsistencies in the PPE fit testing programs across our public health system," secretary Beth Mohle said.
The government will require that all staff working with COVID patients be fit-tested and fit-checked at the start of each shift, a plan that was welcomed by Ms Mohle.
As of May 10, all staff working with COVID patients must be fully vaccinated as well as having PPE checked, Health Minister Yvette D'Ath said.
"(These) are the steps we've taken as a consequence of the audit," she told reporters.
"The majority of hospitals are all doing the right thing and have been doing this but we know we can do better."