I just got an aswer from the Digital Yacht company:
The AIT1000 requires its own GPS
antenna and dedicated
VHF or suitable
splitter like our SPL250. We also have a small HA156
dedicated
AIS antenna which is like a small helical whip and can fit to the
stern rail
The AIT1000 can provide a
NMEA feed to an E series of GPS and
AIS data, so in
that case you would not need a Raystar 125 antenna.
Theresa