Raymarine AIS, bearing at CPA included?

[jonjo]

I am thinking of buying one of the new A50 plotter units as I wish to have more chart resolution than my current RC400 mounted at the helm.

The A50 can display AIS target info which would be a bonus on top of a 4x resolution improvement, however the Raymarine docs don't mention whether they compute and display bearing at CPA (bCPA). After using a laptop AIS program for 3 years I find bCPA essential for collision avoidance decision making.

I doubt many here have installed a new A50 or A70 as yet but could someone confirm if the Cxx and Exx plotters display bCPA?

 

[Boomshanka]

Can't answer the question I'm afraid, but I'd be interested to find out how you get on as I'm just about to replace a RayNav300 with an A50 and put the AIS unit in at the same time. My main concern is that looking at the rear of the unit (at the bottom of this page for instance) the Seatalk cable on the left looks different to the 'old' raymarine seatalk connector... so I'm trying to find out if the A50 will be able to hook up with the other ST60 instruments on board without the expense or hassle of having to change the Seatalk cabling.

 

[PembrokeshirePromise]

I don't think it does give bearing - just time and distance

see:
http://www.panbo.com/assets_c/2009/04/Raymarine_AIS_status_icons-319.html

(I had to find a screenshot to check ....) - I've got c80

 

[jonjo]

[ QUOTE ]
I don't think it does give bearing - just time and distance

[/ QUOTE ]
Ho hum, that is what I recall from a forum discussion thread a couple of years ago.

The omission of bCPA surprises me because I assume the projected target vector line on screen is against my current position and not where I will be at CPA. With a CPA = 0.1 nm and say tCPA of 5 minutes the graphical overview of events won't always indicate which way to turn.

I wonder why active Raymarine AIS users are not jumping up and down protesting? After all the software will have bCPA to hand internally so it is just a matter of popping the number out on the screen.

 

[PembrokeshirePromise]

I agree - I had just such a situation last w/e - though I was stand on - and in the end the tanker did alter course - by all of 5 degrees to clear a safe distance in front of me - without the AIS I wouldn't have known he had even seen me I suppose.

As you say - it would have been useful to know which way was best to turn in advance.

Mind you I'd settle for Raymarine fixing some of the calculations that are just plain wrong - though to be fair they only become really obvious on very long passages.

 

[Dann]

I am not aware of any standalone chartploters that give bCPA. A few PC based chart software systems do. In my mind the lack of bCPA on AIS displays is a major failing. As you say, the info is available so why not display it; it would be of great assistance in making decisions for collision/close encounter avoidance.

 

[mldpt]

I Have a C120 and it does transmit CPA distance and time until, its great I would think the A series will do also but am not sure.
Mike