Some possibilities:
Someone had forgotten to re-enter data and/or for some reason turned it
off.....
The system had gone belly-up.....
Some radio anomolie and you weren't getting his signal (I get this a lot.
Can be close aboard and all I get is an MMSI number or nothing at all).....

AIS is great but not perfect. I've experienced all of the above when no
signal received from a particular source. Generally has nothing to do with
their particular flag State.

otn



"claus" wrote in
:

We have just installed an AIS receiver onboard our boat - and it is a
great help when navigating in Puget Sound with lots of traffic
including ferries, commercial shipping etc.

I was surprised yesterday to see that a Korean containership - the
Huyndai Patriot - was barreling through the busy waterway at 20 odd
knots without transmitting an AIS signal, since that is a mandatory
carriage requirement inder the Safety of Life at Sea (SOLAS)
Convention.

Is South Korea not a member of SOLAS? Is there any penalty for vessels
not adhering to the mandatory requirements in U.S. waters?

Just idle curiosity...

Claus