Shadow AIS signal of my ship

[wholybee]

While approaching Panama I experienced something I have never seen before. A shadow of my ship appeared to be following me about 0.5 miles behind. Apparently my AIS signal was being received, and then retransmitted. Also note that it shows as Class A, in fact I am class B.

I can only assume that port operations is doing this, but why?

Odd, and potentially dangerous? What is displayed on other vessels screens when they receive 2 AIS signals with the same MMSI number? And that one of them is delayed by apparently several minutes to be .5 miles behind my actual location?

Also, I can hide this in OpenCPNs settings by having it ignore my MMSI number. But then will it also ignore my MOB device programmed with my MMSI number?

[GILow]

I get something similar from time to time, but nowhere near anything that I could imagine would be retransmitting my AIS signal.

I’d always assumed it was some kind of inaccuracy in either the AIS or plotter position interpretation. It seems to come and go.

FWIW, this is with a Matsutec AIS connected to a Raymarine C120 plotter.

[wholybee]

This is absolutely something retransmitting my AIS. First it is class A. And second, I don't *ever* see my own ships AIS signal. It is transmitted, but not received by me. This is with a Vesper, OpenCPN, and Navionics.

I have circumnavigated, and Panama is the only place this has happened.