T&T: AIS

[Hans]

Having just finished reading the latest issue of Passagemaker I am more
confused than before.
The article states that commercial "big" ships need to invest in the very
expensive "A" type AIS.
And that the "B" is not yet approved and that the "B" is not a transponder but
merely a receiver!

Am I totally misinformed about this electronics piece or is the article bass
ackwards? I was of the impression that the "B" was receiving on two channels
and many of them (or all) would be transceivers, and therefore much more
expensive. I believe that the "A" type can be had for around $200 and the "B"
for $600 and up (when they go on sale).

Can anybody clarify this for me?

Hans