Go to Pages 107-109.
THese deal with the Com Port configuration and a AIS settings.
I believe you'll need to configure which (Com 1 or 2) port you use, make sure its set at the highest baud rate so the AIS will provide information, etc.
Then there are setting for the AIS display that you need to adjust -- I don't know if there's an AIS not displayed option...(It wasn't clear from my viewing over the web.)