I didn't think anyone was that dopey to think marinetraffic.com could be used as a real time AIS plotter.
For a start it doesn't calculate CPA.
But marinetraffic.com is very useful to those with an AIS Transponder because when in a port that has coverage you can check that you are transmitting.
Plus you can add a photo or two of your boat so other users can see what you look like.
And as a foreign flagged boat cruising the USA I like to have plenty of records of where I am to keep Big Brother happy. As I'm not an illegal drug running criminal I don't need to hide.
Proper AIS, the transponder, is the best advance in marine safety since GPS
and should be a requirement for all vessels going offshore for more than a day sail.
I commend anyone who doesn't have one to start saving up for a proper transponder. The receivers aren't worth a pinch of poop IMHO.