Originally Posted by daddle
I too think AIS
is relatively useless. However a few days ago while being slowly overtaken by a large cargo ship I used the AIS
to advantage. It was advantageous if I could cross his bow but in the rough fast conditions I found it difficult to estimate the safety
of such a bold move. The OpenCPN
plot said "Go for it!" It would have been pathetic to slow this girl down and take the indignity of his stern. Heh.
And I figured he had probably computed my crossing as well and would consider me a fool to not take his bow. Eat my wake suckkkah!
Why did you not contact the vessel concerned? Trying to cross the bow of any ship is not all that smart. He should know your intentions and you his.
Let's take a situation I was in recently coming back from Mexico
on the "bash" to California
. It was a windy, wavy night and visibility was poor, radar
was working but only at a fairly short range of a few miles due to the rolling and pitching of our 38 foot Hans Christian, lots of sea scatter and false echoes. On our AIS screen
a large cruise ship
showed up at about 18 miles, The CPA (closest point of approach) showed as less than 1 mile, I waited a while and then followed the correct radio
procedure and asked the officer of the watch what were his intentions. He replied that they had out AIS signal for quite a while and were altering course to give a 2 mile CPA. No sweat and no surprise. If we were not keeping a good watch the cruise ship
would have made the course alteration anyway, very reassuring.
I recently asked the skippers of the last Clipper Round the world race
what was their most valuable piece of equipment
, and they all agreed to a man it was the AIS transponder.
My experience described above was typical of many situations that we encountered both sailing to Mexico
and back. AIS properly installed is increadably valuable.
I don't see why any commercial
vessel using class A would filter out class B signals. No commercial captain
wants to run the risk of loosing their license
running down any size vessel. I leave the AiS transponder on at all times except when on our slip.
In the event of a sinking the USCG keeps a track of all AIS within its range, and that extends well beyond line of site, I don't know how they manage to do this, but they do, so they will have a accurate position of all transponders in US costal waters. Big Brother? You bet, but I love it!!!