There are a number of sites that do this with naval transponders (an example of one). Generally, I believe it’s expected that civilian vessels have their transponders engaged (especially in national waters), though I’m not sure there are any strict requirements (or even realistic enforcement mechanisms) once one reaches international waters.
Is there a yacht tracking site like the ones people have used to track private planes?
There are a number of sites that do this with naval transponders (an example of one). Generally, I believe it’s expected that civilian vessels have their transponders engaged (especially in national waters), though I’m not sure there are any strict requirements (or even realistic enforcement mechanisms) once one reaches international waters.