Quarantine flags 



SEARSPORT — Staff at the Penobscot Marine Museum delved into the maritime history of quarantines in the museum’s May newsletter. 

During the plague in Venice in the 1300s, they said, foreign ships suspected of carrying disease were required to sit at anchor for 40 days, ‘quaranta giorni,’ before landing their cargo. 

Over the centuries, ships with sickness on board have traditionally flown yellow and black signal flags, or Lima flags. “In 1832, the practice of flying the L flag from the top of the main mast began to signify sickness on board,” the newsletter stated. Today, a plain yellow flag “denotes that a ship has been cleared by the port authority of any serious health problems.” 

The 1923 “Manual on Ship Sanitation & First Aid for Merchant Seamen” lists the length of required quarantine for common illnesses of the day. According to the newsletter, “Cholera with a 5-day quarantine period; plague and yellow fever with 6 days; typhus with 12 days; small pox with 14 days; anthrax and leprosy…never cleared for disembarkation.”