Is AIS in the house?

Only one reason I used a clam shell: That's what had been used for the other antenna! When it was set up by EQ Marine, I assume.

And no, I used polysulfide exclusively, but I doubt very much of the polysulfide made it into the hole. I drilled the hole just large enough for the cable to fit, so there's no effective way to apply any material to the inside of the hole.

If it were cored with balsa, I would have painted the inside surfaces with epoxy and let it set up, but since it's monolithic fiberglass the whole way through, I didn't need to do that.

I just packed lots of polysulfide around the cable and pushed the clam shell over it. If it fails, I will probably drill holes for the clam shell and mount it the conventional way.

Anyway, let me be clear that I don't claim to be doing any of this RIGHT! I just do my best, and I publicize what I've done. I learn a lot when folks ask why I did it that bonehead way instead of the easy way everybody else does it! :-)

So let me ask: Why should I have filled the area under the clam shell with silicone? I don't know this.
 
I have used the packing gland type of fittings if I was just putting the cable thru the cabin top. If I had to put a larger fitting (such as the radar or GPS) I use the Cable Clam. The issue is will there be a leak around the cable? How easy will it be to remove the fitting and thread another cable thru? Definately if the top is cored, you need to undercut the core, fill with epoxy and then redrill/smooth to the cable size. Will the clam shell ventillator pull off with polysulfide?--probably not. I have used the clam shell over the transom on the inside and on the inside of the boat on the overhead. I use very short screws, which don't go thru the overhead. I also fill the hole with silicone, to assure that it will not leak.--
I believe that the way I do it, will allow for easier replacement, and is less likely to leak.

Maybe that is "old fashioned"--but the way that I do it.
 
Well, the AIS "B" didn't get on the FCC 26th Feb adjenda for even discussion, let along approval, and so far is not on the next meeting (March 19th)--so something still delalys the approval of the "B" system for recreational boats.
 
img-8911.jpg


I've got my Shine Micro Class-B AIS transceiver up and running on Two Lucky Fish. I've been writing about it over at Navagear.

Up and running
Installation details
Underway
 
Richard -
When we cruised the Black Warrior we used the VHF to identify our location and direction of movement and found that the tow boats were doing the same. El had great conversations with tow skippers (they suggested safe anchorages) and one skipper even told El of a dock where we could stop and get a cup of coffee from his Mom. So, for us, El was our best safety feature on the tight and curving sections of the river.
 
Congratulations Tim on being the first C Dory with A I S "B" Transciever! The class was finally FCC approved Sept 20th 2008, and then the various transpcievers had to be certified. Great job!

How did you work around the "Official: The entry of static data into a Class B AIS device shall be performed by the vendor of the device or by an appropriately qualified person in the business of installing marine communications equipment on board vessels. In no event shall the entry of static data into a Class B AIS device be performed by the user of the device or the licensee of a ship station using the device."

I assume that you have the input to the RayMarine chart plotter--did it seem to clutter up as far as naviation?

Also, I notice that you used a splitter, and AM/FM antenna/ VHF antenna--would you expect better output (ie being seen on the Vessel Transit system) if you used a dedicated antenna--especially one with resonance on the Class B transmission frequency (AIS 1 = 161.975 mhz AIS 2 = 162.025 mhz; the top of the VHF marine band is at 157.425 mhz)? The 162 mhz frequency is enough out of the VHF band to have a potentially high VSR, and thus decrease the transmission effeciency.

Why did you choose this perticular transciever?

Thanks for the great write up.
 
thataway":1rs3y15m said:
Congratulations Tim on being the first C Dory with A I S "B" Transciever! The class was finally FCC approved Sept 20th 2008, and then the various transpcievers had to be certified. Great job!

How did you work around the "Official: The entry of static data into a Class B AIS device shall be performed by the vendor of the device or by an appropriately qualified person in the business of installing marine communications equipment on board vessels. In no event shall the entry of static data into a Class B AIS device be performed by the user of the device or the licensee of a ship station using the device."
Click to expand...
I didn't "work around" it at all. Shine Micro programmed the unit for me. They have a form you can complete online. It took them less than a day to program the unit and ship it.

By the way, I used my BoatUS-issued MMSI, same as I use in my DSC VHF radio. Apparently, I was completely off-base with my speculation that the FCC hold-up on approving Class B AIS had to do with the mixed-up US MMSI situation.
thataway":1rs3y15m said:
I assume that you have the input to the RayMarine chart plotter--did it seem to clutter up as far as naviation?
Click to expand...
No, it's fine. The Raymarine C-series handling of AIS target data is fairly rudimentary; I think it could be a bit more configurable (I want to see vessel names when I mouse over a target), and it could display vector line course/speed predictions, but heck, it works fine.

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I've been using a Milltech SR161 receive-only AIS unit for several months now, and while it's mostly a "cool gadget" for recreational boaters like me, the AIS data has actually assisted with navigation decisions a few times.

The output from the new Class B AIS unit (the AIS-BX), as it appears on my C-80 display, is identical to that received off the SR161 receiver, except that the list populates faster due to the dual-channel receiver onboard the AIS-BX.

thataway":1rs3y15m said:
Also, I notice that you used a splitter, and AM/FM antenna/ VHF antenna--would you expect better output (ie being seen on the Vessel Transit system) if you used a dedicated antenna--especially one with resonance on the Class B transmission frequency (AIS 1 = 161.975 mhz AIS 2 = 162.025 mhz; the top of the VHF marine band is at 157.425 mhz)? The 162 mhz frequency is enough out of the VHF band to have a potentially high VSR, and thus decrease the transmission effeciency.
Click to expand...
That's a good point. As a receiver, the slightly-out-of-tune antenna works fine, routinely showing me targets 20 miles away. Would a properly tuned antenna transmit better? Could be. Could the splitter further degrade the transmission? Possibly, although it's not supposed to, of course.
thataway":1rs3y15m said:
Why did you choose this perticular transciever?
Thanks for the great write up.
Click to expand...
I've been talking with Shine Micro for several months. They're local, and I like to support local brands whenever possible.
 
With an increase of SWR, it will degrade the transmission--and many VHF radios have protection for the finals, so that power is decreased with a high SWR--not sure if this applies to the unit which you have. For reception--any wire seems to do fairly well--sure you will do slightly better with a frequency specific. I suspect that the difference may be more noticiable on reception of another class B unit.

As for the Gill netters--sure wish that there would be a way that they all had AIS, and it would indicate which side their net was set... In some areas, especially around Prince Rupert, in low visability, the gill nets were a real problem, since they were almost solidly set next to each other.

Good on the service for programing.

What data can you see on the RayMarine?--or is it just the vessel icom? Can you get course, speed, rudder angle etc as well as name?
 
Lots of information is available...

dump005.png


It's just a few clicks away. Sometimes, "a few clicks" are difficult to execute, depending on what else I'm trying to keep track of!

Thanks for the comments on antenna issues. I REALLY need to find another Class B-equipped boat to do some testing with!
 
Thanks, Tim,
This was what I was interested in. I suspect I may go with the Sitex, which has a separate plotter--and that way I don't obscure the screen--I had seen some photos which showed the information on the side of the display.

The United States has been behind in allowing the Class B units, but I do see it as one of the greatest safety features which we have seen in many years. Of course it is no better than the person who is using the data.

Again, thanks for taking the lead.
 
Very interesting thread. I sure can see how useful this would be on the Columbia River.

Is the day coming when active AIS will be on the web, available to all who subscribe?

-Greg
 
timflan":3ucmlri0 said:
Actually, there are several AIS-on-the-web services. My current favorite is MarineTraffic.com, which I wrote about on Navagear.
Click to expand...

Wow. I remember seeing this site a few months ago. The coverage has spread. It will be an excellent resource for night or fog excursions.

Good article. Thanks!!

-Greg
 
Sometimes quite interesting to run one or two of the web AIS sites side by side. They do not always say the same thing.
I can only surmise that they are getting their data from slightly different sources and also processing the reeived data differently.

Fascinating nonetheless to check against what you can see with the naked eye.

We hope to be up and running on AISB soon and will see if we can collide with Tim :shock:

Merv
 
There's some fascinating information here. The first thing that came to my mind was my granddad in his later years use to keep a log book of cruising boats going North and South on the ICW. This was 50+ years ago. He was unable to get out and did this from our front porch overlooking the ICW in NC. With this system and a shore station would he ever have been in hog heaven.

Second thing that comes to mind is it seems if you had a system that broadcasts your position you could track you vessel in the event it was stolen?
 
Marvin, Interesting thought: using AIS as Lojac...Of course you have to turn the system on--or have it turned on, when the boat was started (could be technically easy to do). But then you would need to know the general area that the boat was in, since the VHF radio transmission (on 162 mhz) could be recieved. There could be a national database reporting system, which might be on the look out for stolen boats....but again, I suspect that the smart thiefs would disable the AIS.

There are several security systems which do currently track boats with GPS if they are stolen. These rely either on satellite or telephone communications.
 
Tim,

Posted: Thu Oct 30, 2008 9:44 pm Post subject:

--------------------------------------------------------------------------------

Lots of information is available...

It's just a few clicks away. Sometimes, "a few clicks" are difficult to execute, depending on what else I'm trying to keep track of!
Click to expand...

Congratulations on being a C-Brat first with the AIS-B. So is all the information like you posted from the "Walla Walla" now being transmitted from your boat, so it would show up on, for instance, the Walla Walla screen? You mentioned wanting to be able to hover the mouse/courser over the target. Is that how you get that information up or is it a process of drilling through the C-series menu to get to the AIS info?

Thanks for being out there for us.

Harvey
SleepyC :moon
 
hardee":121msris said:
Tim,
So is all the information like you posted from the "Walla Walla" now being transmitted from your boat, so it would show up on, for instance, the Walla Walla screen?
Click to expand...
NO, NOT all that info is broadcast from Two Lucky Fish. Full-featured ("Class A") AIS includes all that info. But the new Class B specification is different in many ways. Class B is less expensive, lower-powered, transmits less frequently, and includes less "meta data" about the vessel. What's the same: both use MMSI to uniquely identify vessels, and both transmit location, course, and velocity.

In fact, the vessel data for Class B may not include anything other than the name and a classification ("pleasure craft" is how mine's configured). I'm not sure it even includes length, but that seems like the next most important piece of information. See, I've never seen a Class B target depicted. That's why I'm hoping to run into Merv one of these days!

On the C-series chartplotter, you can move the cursor (I know, it ain't a true "mouse-over") over a target, and some basic info will appear. Like this:
dump004.png

Then you can press the button directly below labelled (on-screen) as "View Full AIS Data". So it's really only a cursor-over and a button press. At low speeds, high speeds, or when changing course, however, the screen reorients and redraws in ways that can make it difficult for the cursor-over to "stick"...all of a sudden the target isn't under the cursor anymore!

The full AIS data screen also obscures the chart, so sometimes it's difficult to get the info you want off the data screen and also keep track of what's happening on the chart, and with any kind of distraction at all, it's easy to forget which vessel you're viewing details for. Pretty soon, you're not looking out the windows at all! Be careful to keep your head up; don't "drive the chartplotter!"

I'm not complaining, really. The C-series has been fine, and I'm not going to upgrade it any time soon. But I've also been testing Rose Point Coastal Explorer 2.0, and when you get used to state-of-the-art navigation software, the limitations of the C-series start to become more prominent.
 
Tim,
If you go to one of the AIS channels on the web (not the Greek one) you can pan up to Vancouver BC and find one or two Class B targets. They way they have processed the data it seems to provide essentially the same information as Class A.

I hope to get the Nauticast system installed in next few days so when I get back from European trip we can compare notes and share with the "gang"

Merv
 
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