Question about Marine Traffic (Live Ship)

[Alaskan Sea-Duction]

When I log on and look for the ASD in it home base dock, I don't see here. I see two other boats, George Emery and a sail boat, but I am not showing up. I am transmitting as I have a green light on my AIS. If I do a search for ASD, it shows I am at the dock, yet when I click on the auto-refresh on the left of the screen, it disappears. I should be 700 feet down river from the George Emery.

When we traveled together this last weekend, he had no problems seeing me or I seeing him.

Any guesses?

 

[Nsail]

Try vesselfinder.com also. They'll sometimes show different.

 

[N4712]

My ais wont show my position without heading data.

 

[No Mast]

My ais wont show my position without heading data.

I you're saying your AIS won't show up if you're at anchor say, that sounds odd. Although we currently only have a standalone receive unit pending upgrades, our last sailboat had AIS and we always saw them when we checked, as long as the unit was powered of course.

 

[N4712]

I you're saying your AIS won't show up if you're at anchor say, that sounds odd. Although we currently only have a standalone receive unit pending upgrades, our last sailboat had AIS and we always saw them when we checked, as long as the unit was powered of course.

Iv'e only checked that on Marine Traffic not another AIS unit. It doesn't matter to me as i always leave it and the N2k network on.

 

[No Mast]

oh ok. yes I'm sure a nearby AIS unit will pick you up regardless. Like Nsail suggested, see what vessel finder shows if you're curious. Ive also seen different data between the sites also.

 

[Retriever]

Try vesselfinder.com also. They'll sometimes show different.

Good advice. Marine Traffic doesn't usually cover my marina (Skyline Marina in Anacortes) but Vessel Finder does.

At another marina I frequent (Elliott Bay Marina), Marine Traffic shows fewer than half the boats that are actually transmitting. I believe it has to do with the location of receivers and the transmit power (class A vs B), installation quality, and antenna height of transmitters.

 

[refugio]

Note that these sites use land-based VHF antennas. If that antenna doesn't "see" your AIS transmission (are you in covered mooreage?) you won't show up.

 

[Richard W]

Note that these sites use land-based VHF antennas. If that antenna doesn't "see" your AIS transmission (are you in covered mooreage?) you won't show up.

... and it's crowdsourced, volunteer based, data collection for most parts of the world. The MT, VF, and other similar AIS data aggregation services are not that dependable ... use nearby AIS station on another boat to assert your AIS status.

 

[MYTraveler]

I see two other boats, George Emery and a sail boat, but I am not showing up.

My experience with Marine Traffic is that my boat (class A) will show up (even when all my other electronics are turned off, so presumably no heading sensor, unless my AIS has that built in), but buddies' boats, class B docked near mine, do not. I don't believe it is because of any kind of filtering by Marine Traffic, but is instead because class B signals are not strong enough to reach the Marine Traffic receiver (which in this case is miles away and not line of sight). When my buddy's boat is out of the marina, it shows up on Marine Traffic, presumably because its signal can then be received. At least that is my theory.

 

[Nsail]

ASD, I just looked and, as suspected, you are showing up on vesselfinder.com

 

[Alaskan Sea-Duction]

ASD, I just looked and, as suspected, you are showing up on vesselfinder.com

Cool Thanks. Can you see me on Live Ship?

 

[Nsail]

No, but this isn't surprising to me.

 

[Alaskan Sea-Duction]

Interesting. Another friend of mine checked Live Ship last night about 7 PM and said he could see me. But then again it is Marine Traffic......