> What is the correct filter commands for large ships e.g. tankers, stock > carriers? > > I've tried the filter on symbol "s/SY", however I'm not getting any large > ships. Large ships use AIS, not APRS. If you are only connected to APRS servers, you should not see AIS data. I'm not sure where you would need to connect to get AIS data. Tom KD7LXL