AIS – Universal Automatic Identification System (a Godsend!) and dealing with LARGE ships

Most ocean sailors list ships as their biggest concern, above equipment breakage and seas and weather.

They are fast and, on the open ocean, often “sneak” up on you. You always keep a standing watch, but a 10 minute lapse can result in being overtaken by a ship (you would be lucky to spot a high bridge on a ship beyond 8nm and they can do about 20).

We use radar, with 2 alarm zones, which really helps.

However, visibility is not always good and rain reduces the effectiveness of spotting a ship via radar.

The sighting of a vessel requires a determination of whether you are on a collision course (constant bearing, decreasing range.

At sea, you expect the ship to stay on a constant bearing.

In a coastal or channel situation, there are a lot of ships in near proximity and you can't assume they are on a straight course.

The other big point is that your boat is small and thus harder to spot, you have to assume they don't know you are there.

All ships monitor channel 16 on the VHF, so it should be possible to contact them to sort things out.

However, in reality (my experience) hailed ships seldom respond, even when they have to know you are calling them (remember...you don't know their name). After all, if you're 800nm out and the range of a VHF is about 16nm, who the hell do they think is being hailed?

I have, on the rare occasion, been able to establish radio contact on the open seas.

One was with a huge US container ship and another was with a French ship (they hailed me just to see how things were going, where I was headed, etc....they are big sailing buffs).

Here's one “successful” exchange.

Eric and I were crossing from the Azores and the seas were running quite large.

We picked up a ship on radar and (it was daylight) sighted it on about every 5 wave (remember you both are going up and down quite a distance).

I was confident that they would cross, but I do like to know if they are aware that I'm around (it doesn't hurt), so I hailed the ship at such and such lat\lon.

After a few attempts, a voice came on saying that they didn't speak much English.

I asked if they had me on radar. The response was: No.

I asked if they could see me. Again – No.

Which confirms my general feeling that most ships really don't have any awareness of your presence.

Anyway, I informed him that we were both on a fine course (he probably didn't understand a word I said) and got off the radio.

I often call just in the hopes they hear a voice on their radio and perhaps take a look out the window or check their radar.

I've been told that some of the delay on replies must be from someone trying to find someone that speaks your language, but you have no idea what is going on...again only about 2 in 10 even respond.

But, I've digressed and probably have already covered this in the blog.

We first heard about AIS in Bermuda and I was determined to get one installed and working prior to my English Channel cross.

AIS is used by all ships (above some level) to transmit information.

This information displays on the GPS chartplotter.

The ship shows up as a red triangle.

If the ship is turning, a line appears showing the direction of the turn.

If you select a triangle a text box appears that tells the ship's name, the type of ship, the destination, speed and rate of turn!!!!

First thing....you now have their name and a ship is required to respond when hailed by name!

Note that the name UnKnown is displayed on about 25% of the ships...got to find out what that is all about!

So now you can hail them, you know where they are going (that breaks down when you have no idea where a city is), how fast, how big they are, if they are turning and in what direction and rate...

Eric got this working in the Azores, but then we had problems with it and made the entire cross without it.

However, we got it going again and I have it for the Channel Cross (more to come on that), I can't tell you how nice it is to have information like this when you need it!