For the life of me I cannot fathom why these ships aren’t armed.
Some have armed security, but it can cause trouble. In 2013 India imprisoned 35 security guards who were in their territorial water for “unlicensed firearms” and kept them in prison for 4 years. All were later acquitted, but that doesn’t give 4 years back.
https://www.aljazeera.com/news/2013/10/18/india-arrests-us-ship-crew-over-weapons