Question: What restrictions have been placed on any cruise ship that has left a foreign port?

Answer passage (source: Australia):
page_title: Industry and employers
section_headers: Cruise ship industry
section_content: As of 15 March 2020 there is a full restriction on arrivals of any cruise ship
that has left a foreign port. The restrictions are inclusive of direct
arrivals and Round Trip Cruises (RTC).
This measure will be reviewed after 30 days.
The health, welfare and safety of Australians, both at home and overseas, is
the highest priority of the Australian Government.
From 1am AEDST 16 March 2020, Australia will deny entry to any cruise ship
that has left a foreign port, with the exception of:

Australian-flagged vessels.
International cruise ships en route having departed their last overseas port and destined for Australia.
Australian cruise vessels (domestic cruise ships) operating within the Australian Exclusive Economic Zone can continue to operate without restriction.
Round Trip Cruises that are already in progress and currently returning to Australia.

Cruise ships that do not meet the above exemptions, may be approved through
the Maritime Traveller Processing Committee (MTPC). These approved cruise
ships will be required to go to Brisbane or Sydney.
Crew
Cruise ship crew must self-isolate for 14 days or for the duration of their
stay whichever is shorter.

Reviewer feedback on this answer:
There is a decent amount of information here.  The information is about restrictions on cruise ships.
This provides good details on cruise ship restrictions.

Reviewer ratings:
Excellent
Excellent

Answer passage (source: Australia):
page_title: Coronavirus (COVID-19) advice for travellers
section_headers: Travel to Australia
Cruise ships
section_content: Since 27 March 2020 additional restrictions on cruise ships, including
domestic cruises, have been in place. All foreign cruise ships are legally
required to leave Australian waters and no foreign cruise ships may enter
Australian waters (except for some limited exceptions).
Before this, on 15 March, the Government announced a ban on the entry of
cruise ships that had left a foreign port. Cruise ships could apply for an
exemption to arrive at an Australian port if they were already underway and
returning home.
Australian Border Force and the Department of Foreign Affairs and Trade are
working to bring people back to Australia who were on a cruise when the ban
was announced. They will then work to get passengers to their home
destinations, either in Australia or overseas.
Cruise ship crews are not exempt from the mandatory quarantine requirements.

Reviewer feedback on this answer:
This is about the restrictions on cruise ships.  There could be more information there.
This provides a basic explanation of restrictions on cruise ships.

Reviewer ratings:
Acceptable
Acceptable

Answer passage (source: Australia):
page_title: Coronavirus (COVID-19) advice for travellers
section_headers: Travel to Australia
Spirit of Tasmania
section_content: The restrictions on cruise
ships do not
apply to the Spirit of Tasmania, to allow Tasmanians to travel home.

Reviewer feedback on this answer:
The link goes to a page with a lot of information.  The information is all about cruise ship restrictions.
This only provides a link to the restrictions on cruise ships. It doesn’t provide details.

Reviewer ratings:
Excellent
Could be Improved