An expedition ship departed on an Antarctic cruise mid-March 2020 with no known COVID passengers or crew members. However after 8 days the first passenger became febrile and isolation procedures were followed. A further 24 members of the ship developed symptoms (some as late as 23 days later) with 8 requiring medical evacuation. Of the 217 passengers and crew on board, 128 tested positive for COVID-19 with 81% of those positive being asymptomatic. This paper demonstrates how quickly COVID-19 can spread as well as the high number of COVID positive people being asymptomatic showcasing the importance of testing in this group. Rachael Moses, Multimedia Editor Thorax BMJ, talks to the Professor Alvin Ing, Clinical Program Head, Respiratory and Cardiovascular Medicine, Macquarie University, NSW, Australia, and author of the paper published by Thorax (https://thorax.bmj.com/content/early/2020/05/27/thoraxjnl-2020-215091)