Gordon wrote:
A friend has a 55 foot power boat on which he installed an AIS
transceiver. Obviously, he didn't purchase it in the US.

If you are implying that he has a Class B unit, this statement is true.
Otherwise it is not.

To start with, he had it improperly programmed. It wasn't
broadcasting what he was. (Pleasure boat)
The Coast Guard was warning him (vhf) that he was out of the shipping
lanes, he was crossing the lanes illegally, he was about to go
aground, yada yada because they thought he was a big cargo ship. They
were less than happy when he told them what he was ...

I read this to say that the user does not have the ability to use the device
correctly. Is it therefore surprising that he is getting less than optimal
results, while at the same time causing significant confusion?

Now, if the above examples are valid, what would happen if there was
several hundred small craft putting out AIS sigs?
Would the big guys pay any attention? Would the Coasties pay
attention? Would anybody pay attention? Would everyone just program
the pleasure boats out of their system?
Maybe the US should limit pleasure boat usage to offshore only,
which is really where it is now.

In this hypothetical situation you seem to be asking what might happen if
commercial shipping ignored small craft vessels in the majority of cases.
Would you be surprised to learn that this is essentially what happens
offshore now?

Further, when was the last time the USCG ignored a distress call, even when
it might be bogus?

--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://home.comcast.net/~kerrydeare