The early focus during the COVID-19 outbreak on cruise ships as ‘petri dishes’ of infection has been eclipsed by the enomous economic and health impacts of the pandemic. But early outbreaks on mega cruise ships presaged the global dimensions of the outbreak. The Diamond Princess was quarantined in Yokahama in February 2020 as over 700 of its 3700 passengers were infected and over a dozen died. Subsequently, its sister ship, the Ruby Princess controversially disembarked 2700 passengers in Sydney on 19 March 2020, seemingly the result of failures in Australia’s quarantine procedures. It infamously resulted in 660 cases and 21 deaths in Australia, including seeding an outbreak in northern Tasmania.