Nmea Plus Is the way to go. I downloaded it and Wow!! Fantastic.

It decodes all AIS strings and you can even use it to transmit to other
AIS units too!

I see that these guys are using it to display AIS targets on there website
in real time on real maps!

I just registered my copy and I was blown away by the new features that
opened up. Give it a try.

You can now run one copy of NMEA Plus on one computer (server mode)and run
client versions on other pcs in the same network and display the data on
those pc's too!

http://www.electrotech.net.au/ea_downloads.php