I installed a Milltech SR161 and an antenna splitter on BlueJacket just
before moving it from the Chesapeake to Ft. Lauderdale and I must say that
I was very happy with the performance. My VHF antenna is on top of my 60'
mast and most of the time I saw ships at 40 miles or less. On a less
frequent basis I would see ships at 40-60 miles away and I even saw a
cruise ship at 88 miles away. I was amazed and I realize that it must have
been some strange skip to hear a vessel so far away. In areas like
Norfolk, Charleston and Ft. Lauderdale I regularly had 50+ targets that I
was tracking.

The "no AIS" alarm was a real pain in fringe ares where a single ship's
signal would fade in and out and the alarm would keep going off. That has
to be fixed.

I was using this on a RayMarine C-80 and the biggest problem that I had was
with false "dangerous target" alarms. I have my MARPA/AIS alarm radius set
to 20 miles, such that if a target is within that radius an alarm will go
off. The problem is that all targets, even those at anchor or moored,
cause an alarm. I understand the logic behind this, but in my mind these
are false alarms. I also had problems with some targets generating
continuous alarms, causing me to shut off the AIS alarm. I reported this
to RayMarine and they say that a new version due out in Q1 of 2007 should
address these problems.


Despite the problems that I saw, I wouldn't be without this. MARPA on a
small sailboat underway can't begin to compare with the accuracy of AIS and
its fun to see information about targets such as names, size, type and
destination. I do look forward to getting a transponder when the prices
come down as I want the other vessels out there to see me as well as I see
them.

-- Geoff