I installed an em-Trak 953 last season and agree AIS is an invaluable safety
tool. It allows me to see traffic 20+ miles away. Last season I radio'd a ship several miles away. She told me she saw me awhile ago, had already altered course to give us more room and was monitoring our course.
Another advantage is you're visible on MarineTraffic and other ship tracking apps/web sites. Friends and family
can see where I am (might be a big disadvantage to some!
). This only works when in range of the service's terrestrial receivers. See images
As someone else said, the AIS is also a second GPS device on my NMEA 2000
network. I also connected mine to the nav station chartplotter
via NMEA 0183
for redundancy in case something happens to the NMEA 2000
I went with the integrated antenna splitter and is the newer SOTDMA technology which brought the price closer to $670. I opted for an external GPS antenna ($40) for faster GPS lock because of my mounting location sideways under a wood
shelf. It is still inside the cabin
and would not be needed if I mounted the unit in a different location.
I purchased mine from Milltech Marine
) and found their service outstanding and prices very competitive.
Regarding plug and play, mine truly was plug and play to get AIS information! I did have to change a config setting (very easy) to make GPS data available via NMEA