Who should have AIS B?

[BlueWaterSail]

I think an AIS transceiver should be carried by all recreational vessels when making a passage. That way all ships in your vicinity can be seen, and you are visible to all as well.

For coastal cruising, agree it would just add clutter to the Nav screen.

I would use a stand-alone transceiver w/display (and output to the chartplotter), that way I can switch the other stuff off as needed to conserve power.

BWS

[Lodesman]

Originally Posted by Jentine

I think all non-recreational vessels, including military vessels in transit, should have AIS. If all recreational vessels had AIS, the screen would be so cluttered with bogies that one would have to shut it OFF. Then we would be back to where we were before AIS.

Do you shut off your radar when the screen is all cluttered with "bogies"?
AIS's should have filters to declutter the screen.

[Talbot]

I prefere to know what is coming at me before they know I am there , so that I can make adjustments - that works very well passing through the busy traffic routes in the english channel.

So definitely a vote for a receiver (and software from www.shipplotter.com)

Ferries should already be transmitting on AIS.

What is the point of a fishing vessel having it, they will have it permanently set to trawling just as they leave the visual shape up permanently - it would be a waste of time.

I have used the receiver for some time (NASA) linked to my laptop, but not on my nav screen as it soon gets too cluttered in a busy environment, and the big contacts will be lost in the small ones!

ICOM are already shipping joint AIS receivers with some of their EU VHF radios.

[sandy daugherty]

no ship under 300 T is required to carry AIS, Ferries included.

When you display AIS targets on a chartplotter, you see only those within your selected display range. If its cluttered at a close range, YOU WANT TO KNOW ABOUT ALL OF THEM! And you can swith them on or off very easily.

[Paul Elliott]

I predict that the "Class-B clutter" problem will be worked out long before we have enough installed Class-B units to make a difference. The display software will have selectable filtering that will be looking at range, speed, CPA, TCPA, etc, and will use this info to manage the display and alarms. You will be able to choose what you want to see on your display.

Some currently existing AIS displays will not have this flexibility, but this is no reason to not adopt Class-B for pleasure craft.

I use AIS mostly when at sea and on harbor approaches, where it has been very useful in managing crossing situations -- particularly in low-visibility conditiions (where I also run the radar). It is in the low-visibility conditions where I would like to have all vessels transmitting AIS, not just the big ships. Of course we can't rely on AIS for everything so we continue visual and radar watch, but I still want all the useful information I can get.

I find AIS much less useful when sailing on San Francisco bay, where there are lots of ships on the screen. It isn't the clutter that is a problem, but the fact that the ships are constantly changing course as they transit the shipping channels. Again, I think the clutter issue will be solved by advances in display software.

[rebel heart]

Maybe it's off topic, but I'd rather have more emphasis on basic seamnship and watch standing than more technology. If I had to pick between a mandatory test in regards to seamanship, or a gadget in the cockpit, I'll take the fomer.

[Chief Engineer]

Most people that have radar on a vessel have it because it is cool looking i.e. The Bright clear days and there is the open array just spinning away.
There is a certain need to understand what the radar is telling you. Most don't even take the time to teach themselves.

Originally Posted by rebel heart

Maybe it's off topic, but I'd rather have more emphasis on basic seamnship and watch standing than more technology. If I had to pick between a mandatory test in regards to seamanship, or a gadget in the cockpit, I'll take the fomer.

[Paul Elliott]

Originally Posted by rebel heart

Maybe it's off topic, but I'd rather have more emphasis on basic seamnship and watch standing than more technology. If I had to pick between a mandatory test in regards to seamanship, or a gadget in the cockpit, I'll take the fomer.

If you put it that way, of course -- it's a no-brainer.

But who says this is an either/or choice? I doubt that there are many who honestly think that technology takes the place of seamanship. Those who do probably can't be taught, but only a few of these people are actually going to leave the dock.

Yeah, I've heard the horror stories of people activating the autopilot and going below, thinking that their electronics will steer them safely through the harbor (etc, etc), but these idiots are going to get into trouble regardless of the gadgets they install.

So we can talk about mandatory testing and licensing (in another thread, please), but please don't please don't make this out to be a technology vs. competance issue.

[Sunspot Baby]

We have an AIS receiver, mostly for the comfort of the Admiral. We have had a couple of close encounters with large vessels who did not respond to our hail. Knowing the vessel name might improve our chances of contacting them.

Also, since our old radar doesn't do CPA the reassurance that AIS gives that at current heading and speed we are not about to be run down and sunk.

AIS B? When it it widely used and I am sure of its value, I will add it. This could be a long time coming.

George

[Lodesman]

Originally Posted by Sunspot Baby

Also, since our old radar doesn't do CPA the reassurance that AIS gives that at current heading and speed we are not about to be run down and sunk.

George, I'm curious since CPA is about the most basic function of a radar. Does your radar have electronic plotting or do you have a manual plotting head? From a relative vector, you're able to "see" the CPA and TCPA. Unless your radar doesn't allow the use of rel vectors, you should have CPA available to you.

[sandy daugherty]

Lodesman: MARPA is only a recent (and expensive) feature for recreational radars. AIS gives us CPA on more distant targets, and tells us who we are looking at, what number to dial to talk to them, and [with lesser reliablility] where they are going.

[Lodesman]

Sandy,

Before MARPA existed there were radars with manual contact plotting features - either through electronic plot or grease pencil on the plotting head. But I take your point - and am somewhat embarrassed that my memory is not so good - I have used small Furuno's before that didn't have plotting capability. I think perhaps it was because I used work-around solutions to get the information I desired. If your radar has a "trails" function you can use the trails as reversed relative vectors. If you have a movable VRM/EBL you can drop it on a contact, note the time, then a couple minutes later have a working relative vector (and a pretty accurate CPA/TCPA estimate). If you have PI feature, you can similarly use them to work out a rough relative motion. Or you can drop your cursor on a contact and a couple minutes later, hold a short straight-edge up to the screen between the cursor and the paint for a reasonable CPA/TCPA. If you don't have any of those features, then I suggest getting a grease pencil and plotting on the screen. Even if you do have MARPA, the suggestions above can be used to confirm MARPA info - particularly if it's less than reliable (say if you're flopping around in a choppy sea).


Kevin

[sandy daugherty]

two years ago I was returning from a weekend trip with a group of friends. It was raining, near dusk and I had the JRC 1500 mk II radar on, but couldn't really find a sweet spot on the clutter control, All I could see was Thomas Point Light and the mouth of South River. I turned up to head into South River and a moment later we were illuminated by a VERY bright light, and entertained by five VERY loud toots from a suddenly visible Tugboat and Barge on an imminent collision course. I slam-jibed, jerked a block loose, and one of my guests became hysterical. We missed, by yards. I could see him, his eyes were blue, and as wide as mine. We spoke to each other, in totally unrealistic calm tones on the VHF. He had not seen me either. He enquired if I had any damage or injuries (she was still sobbing in the background,) and I returned the courtesy. We both went on about our business. My faith in my ability to use my Radar was 'adjusted'.
But the one clear message was this. Get, install, and master AIS. Get, install, and master a better Radar. (The JRC is fine, but the screen is just hard to read.) Niether replaces the other. Neither is perfect, but each has strengths in the other's weak points. This event would never have happened if we BOTH had AIS B. I've had an SR-161 (a single channel AIS receiver) for about a year, but it would have had no effect on the incident.

Hysterical Guest is no longer a sailor. Its a shame, she owned a liquor store.

[Pelagic]

In really confined situations like turning into a river, the AIS is great as is a radar that can discriminate at low ranges.

For me, the Radar is invaluable and is my primary tool. So I have invested a lot in equipment and training to get the most out of it.

In Asia, vessels don’t talk much with each other, so maintaining a safe CPA with Radar is your primary job along with finding those unlit fish boats (bancas) that are everywhere.

Over here, keeping a strong lookout and radar monitoring, ......showing exaggerated course changes to demonstrate your intent ........are the name of the game.



AIS does not achieve so much in our application

[Paul Elliott]

Originally Posted by sandy daugherty

This event would never have happened if we BOTH had AIS B. I've had an SR-161 (a single channel AIS receiver) for about a year, but it would have had no effect on the incident.

The tugboats around San Fransico all have AIS-A transponders, or at least all the ones I can see by eyeball are also transmitting AIS-A. Also, the SR-161 and SR-162 receivers should receive AIS-B as well as AIS-A. Of course the chartplotter or computer program that you you have connected to the receiver must be able to decode the A and B messages.

For me, AIS has proven very valuable in low-visibility situations.