Tracking ship traffic via AIS

[sastanley]

Bill...when I was a kid on the boat I now own, we had a VHF radio with a dial and pre-printed channels.....16, 9, 22, couple of telephone channels (26, 27 maybe??) 68, 70, & 83. It was blue & white if I recall. I also seem to recall my Dad saying, 'we need to buy some crystals if we wanted to chat on 72, or 69 like some of our friends.'

So, I am doing a search for 'vintage VHF radios' on google to find a picture of the radio we had...I am having no luck...however, the Icom M422, which I bought about 4 years ago, and currently own, is prominent in the search results.

I also remember we had to have a VHF operators license...WYQ-4569.

Neil, I remember your thread about that...cool stuff.

I have an AIS app from marinetraffic.com on my phone...so, I can transmit my location to that website if I choose..I usually don't, and I am pretty sure it doesn't go anywhere else..just that site. We did transmit however when we delivered Spencer's C-30 from Norfolk this spring so our wives could keep an eye on us for the 96-ish mile delivery.

[Administrator]

I have an AIS app from marinetraffic.com on my phone...so, I can transmit my location to that website if I choose..I usually don't, and I am pretty sure it doesn't go anywhere else..just that site.

For those less familiar with AIS, this approach will let your wife/girlfriend (or both) know where you are, if you and they have Internet service, but it may or may not indicate on your phone the presence of that big cargo ship barreling around Cove Point. depending on the presence/absence of those land-based ears. It's been a while since I looked , but at one point, the Solomons area was sort of a dead spot between our club's ears up north and others down around Norfolk. This was a classic example of ships disappearing and then reappearing.

One of the views on the marinetraffic site shows the areas covered by various receiving stations which feed them data. This is the area covered by our club.
Bill

[Administrator]

North America

This is the current view for most of North America.

[edwardc]

Here on the busy Patapsco, I've noticed the opposite effect, with ships or tugs often disappearing and reappearing on my actual AIS receiver when they get close.

Apparently, some ships don't take care to to have proper placement of their AIS antennas, and parts of the ship's structure mask the signal when close on certain headings.

[toddster]

I was troubleshooting the plotter software Saturday, so I had the AIS on at the dock all day. And I compared my AIS unit display with the ShipFinder App.

Neither my signal, nor that of another class B boat, about 5 miles away, ever showed up on ShipFinder. (A lot of people were broadcasting from the park docks for some reason. I think it was a club event.) Several other class B signals at the same locations did show up. I had previously assumed that my slip is too far from the base station to be picked up. My SWR looks good, so I think that my installation is OK. Everyone uses the same broadcast power (2 watts for class B, IIRC) Next guess is that the boats that get picked up have taller masts. But I didn't drive over to look.

The other thing to note was that with all of the people broadcasting from the dock, the screen was starting to get a little cluttered, except on maximum zoom. I usually flip the "silence" switch when I'm not underway or anchored out. No sense polluting other people's chart plotters. But then you have to remember to flip it back on when you cast off.

I have encountered a couple of tugboats with no signal. I wonder if they forgot to flip such a switch...

[toddster]

This is the current view for most of North America.

I can tell you that at least some of that chart is a bit optimistic. At least, in square 66, only the left edge and a small amount of the left top edge are actually covered. From what I can see when I have my boat here in the yard, I could expand it quite a bit by putting in a base station myself. Not quite that obsessed, though.

[67c&ccorv]

The primary focus of AIS is to see and be seen by other vessels with AIS. They only show up on marinetraffic.com or something similar if somebody with an Internet gateway (usually on land) hears them and uploads what they hear.

I would be astonished if vessels like the Queen Mary EVER turn off their AIS transmissions. The cruise ships which dock in Baltimore never do in this general vicinity. Inside the COLREGS lines, vessels over 60 feet (I think) are required to transmit an AIS signal.

If you see the AIS position of a vessel suddenly disappear as it heads offshore, it's because it moved beyond the range of a land-based set of ears that could repeat what it heard. It's not because the vessel shut its AIS down.

Under certain conditions, AIS receivers can "see" much further than radar. Our ham radio club's local receiver, which feeds various websites, saw a vessel more than 200 miles away last week. Under "normal" conditions, VHF is line-of-sight. Google tropospheric ducting, or join a ham radio club!

Other than a GPS, I suppose, dollar for dollar, an AIS receiver is just about the most valuable navigational aid you can add to your boat, if you share the water with commercial vessels. An AIS transponder (transmit and recieve) is even better, though more dollars.

Someday, all vessels will have them. It wasn't that long ago that VHF radios were something special. My first one was crystal controlled, with maybe a half-dozen channels. Anybody else here that old?

Bill

On my recruit course in the Army we had to learn how to transmit and receive 12 words per minute using Morse Code and key transmitter...was the only way to send comms long distances using a light weight but low powered radio that could be carried by a soldier.

But I am not as old as you Bill!

. --- --

[Administrator]

But I am not as old as you Bill!

Most people aren't!

Bill

[Dave Neptune]

Old is a privelage

My first VHF was also crystal and my license was WTR 3951. I had the radio long before I got the license.

Dave Neptune

[Mo]

It won't be long now and the transmitting and receiving AIS will be about the price of a good radio. No reason it could not be incorporated along with GPS...it's a matter of will to do it.

[Administrator]

My first VHF was also crystal and my license was WTR 3951.

Mine was WAM7326. How come I can remember that, but not what I had for dinner last nite?

Bill

[toddster]

If you sail outside US waters with your VHF, you are still supposed to have a Ships Station License for the boat (WDG4783) AND a Restricted Radiotelephone Operator's Permit (or better) for each operator. I don't know if it's enforced. They are both just pay fee - get ticket sort of deals.

As you probably know, if you go through the FCC this way, you get a universal MMSI to plug into your various digital electronics, including the AIS. If you go through Boat US or the like, for free, you get a bogus one that's not registered with SAR authorities. Or so they say.

Bored, I plugged my zip code into the FCC license search. I'm stunned at how many of my neighbors in this little village have current licenses (mostly Ham, but some odd ones in there too). I've got the only Ship's Station license though.

[Administrator]

I don't think a ham radio license has anything whatsoever to do with a ship's station license.

Bill W2ET

[toddster]

No, they just all show up in the database. Sorry for drifting increasingly off-topic.

[Mo]

If you sail outside US waters with your VHF, you are still supposed to have a Ships Station License for the boat (WDG4783) AND a Restricted Radiotelephone Operator's Permit (or better) for each operator. I don't know if it's enforced. They are both just pay fee - get ticket sort of deals.

As you probably know, if you go through the FCC this way, you get a universal MMSI to plug into your various digital electronics, including the AIS. If you go through Boat US or the like, for free, you get a bogus one that's not registered with SAR authorities. Or so they say.

Bored, I plugged my zip code into the FCC license search. I'm stunned at how many of my neighbors in this little village have current licenses (mostly Ham, but some odd ones in there too). I've got the only Ship's Station license though.

Canada won't push on it but some places in the Caribbean do...I think Bahamas. Yes we should and are "supposed" to have a licence but common sense has prevailed. I've known cruisers going South to the Caribbean that got their radio licence because they wouldn't be allowed entry in certain areas without it.