Len wrote:
On Mon, 24 Oct 2005 11:47:04 +0200, BrianH wrote:

Len, following your post about AIS Live I went to check into what was
active in my cruising area, the Adriatic. Zilch - zero - nada - not a
single AIS equipped ship was reporting in the entire Adriatic Sea,
although clearly the system was active as there were a few clusters
around Malta, Athens and Marseilles when I included the whole Mediterranean.

Is it possible that the web based system you used missed some data
where the ships themselves were actually transmitting?

I really don't know, I just registered and clicked on Med. - Adriatic.

This was AIS Live, from, I think, your own posting. I was surprised
there was nothing shown - and the paucity of ships in the entire Med.
I've just repeated it and the display is similar. Perhaps the Public
site has limited ship data, but the explanation doesn't indicate that:
"As you can see the public site shows a snapshot of vessels with a
random time delay of at least one hour and with only limited information
available." Unless "limited information" refers to numbers of vessels
and not their data as I had inferred.


Now I know there are masses of freighters and large ferries converging
on Trieste, Venice, Rijecka, Ancona, Bari, Split, etc, etc. every day of
the year, indeed, I had a hair-raising close call with a monster, 50
knot, catamaran ferry 10 nm off the Croatian coast last year - but it
would seem that AIS would not have helped me.

You will never know afterwards.
I meant because if the site is a true reflection of the data, it would
not have shown. Had it shown on the screen I could have ascertained its
course; as it was, its approach speed and twin hulls made it difficult
to judge its exact heading.

In my knowledge commercial vessels never switch ais off. What
sometimes occurs is that they don't update their status in time. You
can sometimes see a freighter do 20 kts with the status "moored" or
"anchored". This doesn't affect safety though.


It is likely that all the small companies that can avoid installation
until the mandatory 2008, under whatever regulations they fall under, or
are illegally avoiding installing, or the crews are not bothering to
activate if they are installed, are doing so.

I agree 100% and in a previous post in this thread I already pointed
out one can't rely on one single system and when trusted naievely, ais
(as well as any other system) can lead to unsafe situations. In
intervals intense lookout is simply necessary. The discussion with
Carl is (in my interpretation) focussed on what subsidiairy system to
choose, the enhanced radar-reflector or ais, given the situation one
isn't filthy rich. Of course there always will be ships (fishermen fi)
without ais but there also will always be ships (fishermen fi) that
don't turn on their radar or -when it's operating-, don't constantly
watch their screen or even set the alarm.
Carl suggested not having a boosted reflector would lead to the
situation he would be the only guy getting out of the way. My answer
just referred to the reasons why I disagree on that.

I wasn't arguing with that - I totally agree with you.

Best,
BrianH.