Can anyone confirm the Watchmate gives you CPA (closest point of
approach) but does not give a bearing and range for CPA?
In other words, you don't know if there will be a crossing situation
in front or behind or to one side? So there is no quick way to figure
out an evading course without some mental gymnastics?
Also, I understand the AIS picks up dynamic and programmed info.
Therefore if a tech on the big guy forgets to change the setting from
underway to moored, the his GPS will output a course and speed (maybe up
to 3 kts) to the ships AIS xmitter and the Watchmate (and all AISes for
that matter) will still be generating CPAs etc.
Strikes me that the Watchmate may be a good lookout (do too low power
usage) for passagemakers, but you still need a solid backup of sorts.
Gordon
Comments before I rush out and buy one? ;)

On Aug 22, 12:12*pm, Gordon wrote:
* *Can anyone confirm the Watchmate gives you CPA (closest point of
approach) but does not give a bearing and range for CPA?

It calculates CPA (closest point of approach in decimal nautical
miles), TCPA (time to closest point of approach) and reports range,
bearing, course over ground, speed over ground, heading, rate of turn,
IMO, MMSI, name, call sign, destination, eta, length, beam, type, lat,
lon, underway/anchored etc, and maybe some other fields (the
documentation is a little sparse and it only shows the fields it has
data for). Sadly, it does not calculate bearing at CPA or course to
take to increase CPA to an arbitrary distance. I keep a pad of
maneuvering boards right next to the Watchmate (and my radar) so it
would be simple to do a quick plot but it would be nicer if the WM did
the calcs for you. The WM does have four different alarm profiles
each of which has two programmable filters and five programmable
alarms. The alarms do not depend on the target reporting that it is
underway to work.

I haven't done much testing with the WM yet. I think it will be
particularly helpful offshore. It has been amusing and a little bit
helpful here in SF bay. My receiver (SR161) came bundled with
Seaclear II which is a neat program in a place where you have US
charts and it provides a graphical interface but doesn't plot CPA &c.
Anyway, I've got an SR161 + Watchmate installed and I'm happy to try
to answer any questions.

-- Tom.