Kingfish,
You will need some additional cables and an Ethernet Switch (hub). A four port Netgear Hub will be sufficient. Each NavNet and the BBFF1 will get the below cables.
(3) 000-154-049 NavNet 6-Pin to 6-Pin Network Cables. These cables will connect to the below cables that will then go into the Hub.
(3) 000-144-463 NavNet Hub Adapter Cables. These cables will be used to take the 6-Pin data to a RJ45/Ethernet connection.
Please note that the RDP149 will not share chart data with the GD1900 so you will have to have chart cards in each unit. Also, the GD1900 does not have the ability to show AIS information.
StoneFly