It finally happened to me..FOG AT NIGHT

[JamesTXSD]

Use what you have and know. Learn about the options and decide what works best for your circumstances. And don't let someone on the internet, who may or may not have real world experience, try to goad you into anything.

Better equipment, properly used, makes a difference.

 

[starcrafttom]

I should not but what the hell. . Setting anything but a line of sight compass course on a small motor boat going 18mph or faster is wish full thinking. You can not do it alone thats for sure.

Any modern radar has MARPA and its real easy to use so why would you not use it??

If I did not have radar I would not go out in the fog. If caught in the fog I would work hard to find a place to hide until its gone. Worst case is slow and easy until I get back to a port and hope someone staring at their GPS going 20mph does not run me down.

 

[smckean (Tosca)]

As to radar plotting--I do it in my head. Basically constant bearing is danger, just like visual.

I do the same....more or less. "Constant bearing means collision" is my mantra for avoiding other vessels whether I have an actual visual on the other vessel, or because of poor visibility I only get a bearing to the vessel from a radar screen. Without a knowledgeable crew, as starcrafttom says, that's about all you can effectively do. I have used MARPA occasionally to track maybe one large vessel at a time (who is too big to change course or speed easily), but that's infrequent (but at least I know how to use MARPA!! )

I only brought up MARPA in response to Foggy's point that the regs claim you must do blip tracking if you have radar installed. That's fine in an ideal world, but on a small boat like a CD while alone, or with an untrained crew, it's just not practical......so I guess I'm in violation and will continue to be :wink:. I only posed MARPA in the sense that if you have radar you probably have MARPA, and if you must track, then it seems to me that MARPA is less likely to divert the skipper's attention and time than hand plotting would.

In the final analysis, I am pretty much exactly where starcrafttom is.

 

[starcrafttom]

THEN I learned about AIS. In a w button push I have everything i need to know to maintain collision avoidance,

Well you know about everything that HAS AIS. its all the other small to big boats that do not have it or fail to turn it on that radar covers for me. Great tool but only part of the solution. Still waiting for a sent and receive unit for under $500 before I put it on. Remember most units are receive only. I have talked to several people that got receive only units installed and think that everyone can see them. They did not understand what they were buying but people where willing to sell it to them.

Talked to a guy on a cruising site that was under the impression that having radar made him more visible to other peoples radar.????????????? They are out there and they buy boats..

 

[smckean (Tosca)]

I agree with hardee that AIS is slick, but as starcrafttom points out, many vessels don't have transmitting units, so you can't see those vessels (I presume, Harvey, that this is your case too; so AIS helps you see others, but you are not helping them see you! :wink. I imagine it is great to have AIS blips (and all their associated info) right on your chart plotter with your GPS showing your boat's location on the same plotter; but that costs, and many of the chart plotters out there don't support AIS integration.

There is a "quick and dirty" solution that gives, in my estimation, 60% of the "I see you, but you can't see me" benefit.....namely, smart device apps. I bought a AIS app for my iPhone for $4.00 (mine's called "MarineTraffic"). Since AIS is required on all ships of 300 gross tonnage and all passenger vessels, I can see all the freighters and all ferries on the iPhone. Better would be putting the app on my iPad which I have mounted right next to my chart plotter with a suction cup bracket on the front helm station window. Unfortunately, my iPad does not have cell/GPS support; but if it did, I would have blips for all those big ships around me, and a blip for my boat on the iPad screen right next to my chart plotter.

So if you have a cell/GPS enabled iPad-like device, 4 bucks gets you most of what Harvey is raving about! OTOH, you have to be within range of cell service for this to work -- which is why I only give this solution a 60% grade.

P.S. I'm considering putting a cheap router on my boat giving me a boat-wide LAN using my iPhone as a hot-spot. Then if I buy a GPS enabled iPad (I actually borrow my wife's iPad now which doesn't please her :roll, I'd have AIS, including my boat's blip, much of the time.....not to mention inter-connectivity for all my LAN supported devices (e.g., laptop) without all those wires hanging around as they now do. Also, with a LAN I wouldn't have to pay Verizon for another line just for the iPad.

 

[beermanPDX]

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]

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]

<stuff clipped>
Talked to a guy on a cruising site that was under the impression that having radar made him more visible to other peoples radar.????????????? They are out there and they buy boats..

It does.... a little . 1) one usually has more metal on the roof to support the radar and that plus the internal components of the dome increase the reflection (but I agree that's mostly negligible). 2) IF others have their radar on, you often get a streak when your radar and theirs come into alignment (typically every several turns). This provides a vector as to where they are at. I often see other boats from this vector prior to them being in the display range of my radar.

 

[smckean (Tosca)]

At best it is minutes behind and some times days.

I knew these AIS apps were marginal, but I didn't realize they could be that off. I only use MarineTraffic in more urban and heavy vessel traffic areas, so I guess that's why I've not seen this "repeater" delay. I will readily admit that these AIS apps are more of a toy than a tool.

 

[Marco Flamingo]

At best it is minutes behind and some times days.

I knew these AIS apps were marginal, but I didn't realize they could be that off. I only use MarineTraffic in more urban and heavy vessel traffic areas, so I guess that's why I've not seen this "repeater" delay. I will readily admit that these AIS apps are more of a toy than a tool.

I have an apartment that looks out over Elliot Bay. Watching AIS is really entertaining. I can see the names of the tugs bringing in a container ship, the name of the container ship, info on the ship, etc. But the random refresh times are obvious. I can see a ship out in the bay when the AIS icon shows that it hasn't yet cleared West Point. Not really accurate enough to determine the ship's exact location, but we are used to this type of accuracy in other applications (like my GPS chart plotter) and may assume that AIS can be used for navigation. It is more an aid to entertainment than and aid to navigation.

In the fog, AIS could tell you that there is a ship out there somewhere, but I always assume that anyway.

Mark

 

[rogerbum]

At best it is minutes behind and some times days.

I knew these AIS apps were marginal, but I didn't realize they could be that off. I only use MarineTraffic in more urban and heavy vessel traffic areas, so I guess that's why I've not seen this "repeater" delay. I will readily admit that these AIS apps are more of a toy than a tool.

I have an apartment that looks out over Elliot Bay. Watching AIS is really entertaining. I can see the names of the tugs bringing in a container ship, the name of the container ship, info on the ship, etc. But the random refresh times are obvious. I can see a ship out in the bay when the AIS icon shows that it hasn't yet cleared West Point. Not really accurate enough to determine the ship's exact location, but we are used to this type of accuracy in other applications (like my GPS chart plotter) and may assume that AIS can be used for navigation. It is more an aid to entertainment than and aid to navigation.

In the fog, AIS could tell you that there is a ship out there somewhere, but I always assume that anyway.

Mark

With an AIS receiver, AIS is pretty darn accurate. I have AIS overlayed on my chart plotter and also have radar overlayed. The signals line up nicely.

 

[starcrafttom]

I often see other boats from this vector prior to them being in the display range of my

I have to say that I have not seen that and if you do its just pure luck, but interesting. Now you have me wanting to try that and tune my unit to see it.

 

[smckean (Tosca)]

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]

Somewhere in this thread it was mentioned that such a unit costs around $500.....

This one has me thinking about it @$550. Just finishing up a major electronics install on my Nordic, and it has a couple things going for it I like.

GPS is integrated, so you don't need to rely on it fetching from another device. And, since it's N2K - it's plug and play with the rest of my system, and that integrated GPS can act as a backup GPS to my other components should the primary fail.

 

[smckean (Tosca)]

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]

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