AIS at the chartplotter

Sandy said:
more importantly has not moved from that stanchion, is all you need to work out what is going on.
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You must sail on very flat waters and have an extremely well balanced sails. On my boat, ships jig about from one stanchion to another!
Rather than using stanchions, I'm surprised that you haven't upgraded to a Pelorus, or is that also too modern ?
 
ip485 said:
AIS is just another tool. If you sail at night, in fog or even bad weather it can be a very useful tool. Its no more vital than light aircraft often having neither traffic avoidance or a transponder (the equivalent of AIS) but there are times its nice to eliminate luck.

Dont be a technophobe, it is a nice tool, and if you have the funds, I would add AIS.
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Although a useful tool in fog, whether it adds to safety or not depends on the extent to which it tempts sailors to set off in marginal conditions. For myself, I have radar and AIS. I consider the radar as a useful safety device but I value the AIS principally for the additional pleasure it gives, by saving time checking ships' courses and the extra confidence it gives my wife. I like to think that class B does have some safety advantages too.
 
johnalison said:
Although a useful tool in fog, whether it adds to safety or not depends on the extent to which it tempts sailors to set off in marginal conditions. For myself, I have radar and AIS. I consider the radar as a useful safety device but I value the AIS principally for the additional pleasure it gives, by saving time checking ships' courses and the extra confidence it gives my wife. I like to think that class B does have some safety advantages too.
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Good points. I mean aviators have flown around for years with neither. There has never been a mind air in cloud in the UK, although to be fair we talk in three dimensions, not two. I bet you could sail around a long time in fog or tucked up in your bunk and never hit another yacht or ship, the more so if you gave the busiest places a miss.

Trouble is as humans, well we are human and dont base our risk assessments on proven stats.

So we like to shift the odds even more in our favour!

Hence your wifes extra confidence.

Cirrus have sold more million pound four seaters, not because the pilots wanted a chute, but the wife did.

I like the idea it gives the confidence to set out in challenging conditions. Dont do it just because of the AIS or radar, but do it because you would otherwise put off that beautiful mile eating night sail because you cant see.

As to which as I know you know there are lots of vessels without AIS and especially the smaller stuff, which can be more difficult to see as well because of their size. Fishing boats are the classic example, two men and a rod in a 20 footers, happy to be 4 miles off in the pitch black of night with a few pork pies and large cans of the golden liquor. Why they do it is beyond me, but these be tough fellas, who have always fished that way it is just another lads night out.

You see them on digital radar, no chance with AIS. I am motoring at nearly 8 knots in 26 tons and I dread the thought of spoiling their lads night so I do run radar and AIS and take a strange pleasure from watching how closely they tally when the vessel also has AIS, after all something to do with those dark watches. Radar may go off ten miles of shore, although I recall the strange story of the shout off Pevensey, one of the noght out brigade in a Zodiac between the seperation lanes, only just mind you, and genuinley it was no lights, no radar, no AIS, cans of the golden stuff and pork pies and apparenty they said nothing like the first time!
 
I only fitted AIS at the beginning of last year so hardly used it for real yet. I think that I have got the settings correct now, as to start with it said every vessel was on a collision course, even those at anchor. Hopefully I will get more use of it this year. It is another tool for collision avoidance especially for cross channel trips.
 
Boathook said:
to start with it said every vessel was on a collision course, even those at anchor
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Getting the CPA (distance) and time to CPA alarm settings to your liking make for a happy coexistence with AIS.
I set the CPA alarm to 10 miles and turn that alarm off and time to CPA alarm to 15 or 20 mins and leave that alarm active. Others might like more warning.
 
LadyInBed said:
Getting the CPA (distance) and time to CPA alarm settings to your liking make for a happy coexistence with AIS.
I set the CPA alarm to 10 miles and turn that alarm off and time to CPA alarm to 15 or 20 mins and leave that alarm active. Others might like more warning.
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Depending on your system, you can also turn off warnings from any vessel which is going below a certain speed so that vessels at anchor or manoeuvring slowly do not appear to be on a collision course. This certainly helps when the target vessel is in a different bay to you or the other side of a headland and any collision would actually involve a collision with land rather than the other boat. :(

Richard
 
But predicting collisions with anchored vessels can be useful in strong tides as found in the ship anchorage east of the isle of Wight.
 
DJE said:
But predicting collisions with anchored vessels can be useful in strong tides as found in the ship anchorage east of the isle of Wight.
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Yeah, another technique to get the best use from the kit. Great to practice too before having to find out in poor visibility, rain...oh and rain!
 
capnsensible said:
Yeah, another technique to get the best use from the kit. Great to practice too before having to find out in poor visibility, rain...oh and rain!
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I'll arrange a poll to see how many AIS users use their kit to assess whether they are on a collision course with a stationary vessel.

I've a feeling that it's going to be a rather one-sided result. ;)

Richard
 
RobbieW said:
No doubt, but there are people who dont appreciate that thier boat is not going where they are pointing it. Unfamiliarity with the idea that the 'road' is also moving perhaps...
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Some people don't sail in strong tidal areas and perhaps don't fully understand how useful this top tip is.
 
Rounding the Lizard, motoring bound Falmouth, Midnight Aug 2015 against oncoming Fastnet race fleet.
AIS targets on PC screen using open Open CPN .
Its the ones without AIS that you still has to be on the look out for.
Radar almost a wipe out in these close quarter situations so Mk1 eyball as well.
A very stressfull couple of hours. Some Yachts correctly lit some not.
The fleet had been waiting in Falmouth bay for the visibility and wind to improve , so we caught the whole lot at once.
So AIS is a useful tool in the kit.lizard3 fastnet.jpg
 
RichardS said:
I'll arrange a poll to see how many AIS users use their kit to assess whether they are on a collision course with a stationary vessel.

I've a feeling that it's going to be a rather one-sided result. ;)

Richard
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Perhaps not if you phrase the question carefully to include stationary vessels which are moving relative to the water.
 
rotrax said:
Quite right Richard - Mk 1 Eyball deals with that! Even at night.

Moving targets are its best use, targets moving at high speed comared to the speed of a yacht.
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It doesn't matter, Mr. R what speed the contact is making. One knot, ten knots, forty knots.....or stopped at anchor. Yer AIS is telling you, as best it can, Closest Point of Approch. I sure you know this! So if that CPA is zero, then you have a risk of collision that needs resolving. ?
 
RichardS said:
I reckon that "anchored" covers that. ;)

Richard
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Perhaps include this as a reminder.

tide-on-buoy-2.jpg
 
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