It finally happened to me..FOG AT NIGHT

beermanPDX · Posted: Thu Oct 12, 2017 5:23 pm Post subject:

Harvey has AIS transmit function as well, so he's definitely helping others see him. He has one of the Vesper units with the display I believe (Watchmate???)

You have to be careful with MarineTraffic. It is not a replacement for AIS in my mind. It relies on AIS base stations to pick up the AIS VHF signal and put it on the internet for MarineTraffic to use. I've seen situations where there was quite a delay.

I have the Si-Tex MDA1 on my boat. It was pretty close to $500 so relatively affordable on the boat electronics scale.

starcrafttom · Posted: Thu Oct 12, 2017 6:05 pm Post subject:

have to agree with Rob about Marine traffic ( which I have and use, even on my desk top at home to keep a eye on my folks) . At best it is minutes behind and some times days. Thats right, That icon for harveys 22 can be from several days ago and was the last reported position. But unless you open each icon you dont know that. And in the SJ's cell services is less then useful most places. I use it to find people I want a location for and not for real time positions.

rogerbum · Posted: Thu Oct 12, 2017 6:36 pm Post subject:

smckean (Tosca) · Posted: Fri Oct 13, 2017 12:26 am Post subject:

Marco Flamingo · Posted: Fri Oct 13, 2017 10:48 am Post subject:

rogerbum · Posted: Fri Oct 13, 2017 11:33 am Post subject:

starcrafttom · Posted: Fri Oct 13, 2017 11:59 am Post subject:

smckean (Tosca) · Posted: Fri Oct 13, 2017 12:02 pm Post subject:

I'm glad to know about this delay problem. I'm sure it's always been there for me, but having radar, I've never depended on AIS enough to notice it I guess.

Time for me to start thinking about installing a true AIS receive and send unit. I'll have to look into whether or not my older chart plotter can be integrated. Somewhere in this thread it was mentioned that such a unit costs around $500.....it that about correct (hardee?)

Da Nag · Posted: Fri Oct 13, 2017 12:22 pm Post subject:

smckean (Tosca) · Posted: Fri Oct 13, 2017 5:22 pm Post subject:

Thanks Da Nag. I'm putting this on my "do relatively soon" list. I confirmed that it is compatible via NMEA with my 12 year old RayMarine MFD.

BTW, the link you provided is for the 6000 model; I note there is a 8000 model for $200 more. The 8000 has lots of "nice to have" features; and when I get time, I'll look to see if maybe some of these additional features are important. One thing I did notice with the 8000 is that it has a built-in WiFi router. So if I installed this 8000 unit for AIS, I would get my long desired on-board LAN automagically. The 6000 would require a USB cable or LAN dongle to connect it to a LAN (plus a separate router of course). I don't think the 8000 has the internal GPS antenna, so that's a downside; but OTOH, the internal GPS isn't much good unless you mount the 6000 on the roof of the boat (or somewhere with a near unobstructed view of the sky).

P.S. The install manual (same manual for both 6000 and 8000) says one can not share a GPS antenna, but these AIS units can supply GPS data via NMEA to other units. So I'm thinking maybe I could switch my existing GPS antenna from my existing GPS unit to this AIS unit, then make a NMEA connection to my GPS, and thereby effectively share the single GPS antenna.

hardee · Posted: Sat Oct 14, 2017 12:03 am Post subject:

The internet provided AIS is useful, and I use it to confirm my transponder is putting out an active signal, BUT, Marine Traffic and Boat Watch both are not real time, and that is important to understand. In most cases, it is fine to use, but I would not rely on that for anything closer than 3-5 miles due to the time delay possible.

By the time you spend the $$$ do the go around, you can probably be into a good marine VHF that has AIS receive and that will have a display on the VHF and also output to your plotter. Most every brand available now will do that through the NMEA cabeling. That will also give you AIS in real time, invaluable info.

And yes, not every boat has an Active AIS device (Class B transponder), but as noted, the big ones do, and since in reality, Tonage rules, those are the big concerns first to avoid. The smaller ones probably won't have radar reflectors, fog horns or anyone with much in the way of common sense, so now you will have more time to be watching out for them.

I know my radar reflector, fog horn and nav lights don't make me impervious or super mariner, but with those, plus the radar, plotter overlay, AIS, windows open and dead slow speed, (up to this point), I have been able proactivly avoid possible close encounters on severa occasions. (Yes, I had a guy in a tin boat, doing 15 knots in less than 100 foot visibility, head down watching his hand held GPS, cross my bow, 50 feet out, nearly jump out of his boat and skin when I triggered my fog horn mid cycle as he crossed my bow.)

Harvey
SleepyC Moon