The Inge Kosan is currently anchored off Mooloolaba on the Sunshine Coast with state authorities containing and treating the active cases aboard the ship.
The Queensland government forewarned on Wednesday that more cases could emerge on ship.
Consideration is being given as to whether infected patients can be quarantined on the vessel to reduce risk to the rest of the crew.
The Maritime Union of Australia is continuing to call for an independent investigation into the death of an Inge Kosan crew member whose body washed up on a beach in Vanuatu two weeks ago.
Chief Health Officer Jeannette Young has issued new health directives regarding interstate outbreaks, which will take effect on Thursday night.
Under the new rules anyone who has been to an interstate virus exposure venue during the exposure period must quarantine and get tested.
People who are identified as close contacts of known cases will also have to go into quarantine and get tested.
Australian Defence Force or international air crews will be allowed to leave the state before completing quarantine if they have no symptoms, travel directly to the airport by private transport and depart on a crew-only flight in which everyone wears face marks.
Visitors, staff or volunteers will be banned from entering hospitals, residential aged care or disability provide facilities if they’ve visited interstate exposure venues or are identified as close contacts in the previous 14 days.
The new health directives will be in place indefinitely and automatically come into effect whenever an interstate outbreak occurs.
Young said in a statement the directives would all be in effect by 10.30pm on Thursday.
Queensland Health on Thursday also reported a fourth positive case who was already in hotel quarantine after arriving from Papua New Guinea.
The state conducted 6362 virus tests and administered 2379 vaccine doses in the 24 hours to 9am on Thursday.
Queensland has now given 141,866 doses since the rollout began on February 22.