The word ‘quarantine’ does not appear in the current International Code of Signals (ICOS). While older versions had codified signals for various quarantine messages (from the prosaic ‘my rats are dying’ in the earliest codes in the 1700s, to ‘I have or have had a contagious disease aboard’ in the editions of 100 years ago), that practice was dropped when the code was overhauled in the 1960s. It was the golden age of vaccines and medical triumph over epidemics: polio was beat, smallpox long gone, yellow fever and cholera could be treated, public vaccination programs were in broad swing, etc. There was no need for such a code anymore!
However, the world has changed and quarantine is the word these days. Therefore, to signal ‘quarantine’ today, a vessel could use either one of the following:
Probably the second is the most accurate for a vessel in quarantine, but either will do.
How I Fixed the Internet (really!)
When the pandemic of COVID-19 began in 2020 the Internet scrambled to find out what signal flag should be used for vessels in quarantine. Scores of blog authors, Facebook posters, Twitter tweeters, maritime information sites and others, sought the correct symbol for this new and novel vessel status.
And they all descended on Wikipedia, where the corresponding entry read:
Sadly, none seemed to note the footnote shown above and only seized on the L-for-Lima flag as the symbol for quarantine, unsupported by international custom since the 1950s.
The state of Alaska proclaimed the Lima flag as the appropriate international naval symbol and the town and Harbormaster in Newport Rhode Island jumped on board:
I began a personal campaign to fix the Internet. I corrected the Wikipedia entries and footnotes (Wikipedia is indeed ‘the free encyclopedia that anyone can edit’) with the appropriate footnotes and citations, created a form email I began sending to pages all over the world that had the wrong information, and shared the correct protocol via Twitter tweets and Facebook posts.
Informed of the error, most were thankful for the updated information and corrected their posts within a day or two.
All is well in the world now. The Internet has been fixed (somewhat).