Your questions (bg9208) are so good I don't have the answers!However, if you have a big
budget you will end up with latest
Raymarine kit including
AIS (Automatic Information System) overlay of ship's (so fitted and turned on) positions overlaid, and able to query their name and mmsi No. to contact them if need be on your
DSC radio VHF. Your radar and chart will also overlay.Scanners vary by manufacturer type and within this also vary by age of
equipment (i.e raymarine have changed format of signal.I have used some new Raymarine
equipment this week under pressure and ther is no doubt that many of the features are valuable and innovative.
For myself, having changed vessel about 9 years ago, matters are more simple.
A lorenz 7 suncolor
chartplotter has two positions and drives the
autopilot.A PC
laptop down below drives another chartsystem, and accepts input from a normal MLR
GPS.
Passage planning is done here and tricky pilotage too.Depth is output from an Airmar
transducer NMEA type bonded to the
hull inside with modelling clay. This is in addition to the Raymarine
transducer going directly to the
seatalk bus.The Airmar shows up on the Lorenz 7" suncolor plotter
screen as a graph like a
fishfinder, but without the fish! Paper
charts are also carried to mark our track at hourly intervals in case of
power outage. In addition another backup
laptop is carried with its own mouse
GPS.Quite often in challenging situations, another producers electronic chart is cross checked if queries arise. A handbearing
compass is often used to check that the bearing of nearby vessels does in fact change.
Little has changed, except that your underlying earlier
navigation skills are still essential to the safe operation of the vessel.Under pressure you will find yourself reverting to the Douglas Protractor and paper
charts.
I intend to fit a stand alone radar this season a
Furuno 1623 and hope that when this is interfaced with the GPS it will be as useful as
AIS. I notice that four
trawler on my last voyage in my vicinity did not have AIS fitted, so would have been invisible in
fog.
Positively, AIS can see a vessel like a
Ferry around the other side of a headland!
Radar sees rain squalls, AIS does not.
The more
NMEA listners and talkers one connects, the more the neccessity of haveing a small interface box (Actisense make them) or a Raymarine interface box to convert
Seatalk or its successor to NMEA
instruments. Even NMEA is changing to a faster protocol so look this up too!Best of luck!