Class B AIS waste of money

[rwidman]

Originally Posted by SV Enough

I'm hoping to prompt some discussion on what a total waste of money purchasing and installing a class B transponder on your please craft is.

If your objective is is "be seen by commercial traffic", forget it! I personally have been summoned to the bridge to SPECIFICALLY check Furuno/ECDIS radar settings and ensure that "except class B" is ON, meaning exclude them. For proof see

Class B AIS - Filtering Of Targets By Ships – gCaptain

Mark Fay,
Merchant Marine Credential Jr. Engineer, QMED, AS-E / MSC ET

I'm guessing you would believe a receive only AIS setup would really be a waste of money, right?

I think these options are available because we don't all have the same needs. I have no AIS at all right now and I'm doing fine. If I boated where there are a lot of big ships, I would probably installed one by now but I'm not so concerned with ships seeing me as with me seeing them and knowing if we are on a collision course.

[Don1500]

Going north from Fernandina to Port Royal I crossed the entrance to Savannah. While going past (at 10 PM) I saw lights that I didn't understand because of their height and color (A green and a white to either side of the green) I assumed that it was a ship (I assume everything is a ship) and made sure I would not interfere with it. I passed about 3 miles in front of what turned out to be an empty car carrier (looks like a building, huge!). There were also numerous other ships moving about or at anchor but none were in conflict with me. I had kept an eye on the ship the whole time I was passing it but I know I would have been better informed if I had AIS, and he would have also if I had a transceiver.

I have just bought a trawler and I know I will be traveling up the Chesapeake in the spring then into New York harbor and Long Island Sound as well. I will defiantly have AIS "B" installed before I leave.

[Time2Go]

Originally Posted by Don1500

Going north from Fernandina to Port Royal I crossed the entrance to Savannah. While going past (at 10 PM) I saw lights that I didn't understand because of their height and color (A green and a white to either side of the green) I assumed that it was a ship (I assume everything is a ship) and made sure I would not interfere with it. I passed about 3 miles in front of what turned out to be an empty car carrier (looks like a building, huge!). There were also numerous other ships moving about or at anchor but none were in conflict with me. I had kept an eye on the ship the whole time I was passing it but I know I would have been better informed if I had AIS, and he would have also if I had a transceiver.

I have just bought a trawler and I know I will be traveling up the Chesapeake in the spring then into New York harbor and Long Island Sound as well. I will defiantly have AIS "B" installed before I leave.

No doubt, seeing lights at night can be difficult
However if you can see them,as you indicated you could
Then you absolutely should be able to indentify what you're looking at.
It's a pain but I always travel with a cheat sheet in case I don't remember
what exactly the Christmas Tree of lights coming my way is.
Weems and Plath even make a product I believe is call a
"LightRule" where you just slide the slider to reveal the lights you see
then just read off what the vessel is.
Great for practice too.
IMHO AIS is definitely worth giving up a month of beer for.

[boatman61]

Originally Posted by Time2Go

IMHO AIS is definitely worth giving up a month of beer for.

Either you live in Oz or.. you like quite a few beers.. good man!!!

[Don1500]

By assuming the lights were a ship I did what I believed was the right thing and all was good. Now as for the lights. The two white lights were flood lights on the port and starboard wing bridges, the green was the bow running light, it changed to red as I passed the bow. There was no real "confusion" just wonderment because the Green/Red light was extremely small (about the size I would expect on a much smaller boat or one much further away) and very high off the water, like 100-150 feet. It just didn't look right, but I assumed it was a large ship and acted accordingly. As far as a distance gauge, there was another ship at anchor between me and the other boat. It was about three miles from me so I knew that whatever the lights were, it was at least three miles away. It was a very dark night and I didn't see any shape until I was well past the CPA and had some light behind the ship.

I am just relating this as a way to say AIS "B" would have been very helpful.

[Exile]

Originally Posted by rwidman

Some folks use AIS to let friends track their location or even as a security feature to make sure their own boat is where it's supposed to be when they are not on it. And track it if it's gone missing.

I don't believe that's against the law.

Nor should it be. I just see this on my plotter a lot and was curious if there were reasons beyond just forgetting to turn it off. Apparently many AIS systems are tied into instruments or gps w/o separate switches to turn on/off. But what you & Paul E. have explained about security/tracking also makes some sense. Either way it doesn't seem to interfere with safe navigation around harbors so no harm no foul.

[Time2Go]

Originally Posted by Don1500

By assuming the lights were a ship I did what I believed was the right thing and all was good. Now as for the lights. The two white lights were flood lights on the port and starboard wing bridges, the green was the bow running light, it changed to red as I passed the bow. There was no real "confusion" just wonderment because the Green/Red light was extremely small (about the size I would expect on a much smaller boat or one much further away) and very high off the water, like 100-150 feet. It just didn't look right, but I assumed it was a large ship and acted accordingly. As far as a distance gauge, there was another ship at anchor between me and the other boat. It was about three miles from me so I knew that whatever the lights were, it was at least three miles away. It was a very dark night and I didn't see any shape until I was well past the CPA and had some light behind the ship.

I am just relating this as a way to say AIS "B" would have been very helpful.

It would appear that the oncoming vessel,
the car carrier, was out of compliance for power
vessels greater than 50 meters in length

Bicolour or Separate Side Navigation Lights + 135° White Stern Light + 225° White Steaming Light + Additional 225° White Steaming Light.
The forward steaming light must be lower than the aft steaming light.

Boatman,
gave up drinking many years ago because i
was really really good at it, now just hang with my
British friends, they make up for me

Cheers
Neil

[svinshallah]

A Class A RECEIVER? I know that there are Class A and Class B transponders, but I can't see that it makes a difference for a receiver.

[Exile]

Originally Posted by shawndear

Sck5 you can do what you like. If you are driving and the speed limit is 60mph and you do 50mph because you can’t read or haven’t learnt the signs and think that that’s the best speed, don’t criticise those who know the rules. Sometimes those that know its 60mph will also do 50mph but that does make it law.
Due to your statement you obviously have had no formal training or are so arrogant that you think you can make up your own rules and then bully people and sound so confident that you know what you are talking about when in reality you know nothing about it. This is wrong as you are perpetuating ignorance among newbees and also failing to know the basic rules of the seas.
So for your tuition today I highly recommend that you have a look at the IMO’s (international Maritime Organisation) on Col Reg – (collision regulation). You obviously have no idea what these are, probably never heard of them; but they tell all sea going boats/ships of all sorts what boats/ships they have to give way to and under what conditions. To simplify, there is no rule about size. A ship is/is not restricted in its ability to manoeuvre; in open sea few ships are, irrelevant of size. They all have man on watch and can EASILY change their bearing by 5 degs when they spot a yacht on radar (which they all legally have to have) 15 miles away. They have to give way to the sailing yacht.
To think size or your activity (unless fishing or towing) is something to take into consideration is beyond belief. Imagine the arguments or lies on the radio between two ships that argue who has to give way because they are 1 foot bigger than the other or my job is more important than your job. Or the argument between Club Med (sailing cruise ship) and a similar sized cargo ship. Sail yachts have higher priority over ordinary unimpeded motor boats – learn it. A large cargo ship in open water is not restricted in its ability to manoeuvre. If it were it would have to display the correct day time signals - and they don't. Obviously, ex-cargo ship captains etc would love to perpetuate the misconception that sail yachts are the vermin of the sea, but we are at least the vermin with right of way over them in anything other than a restricted channel.
And remember, you may be sailing around doing nothing but others like myself do it for a living. So under your ridiculous rules I would have right of way over another sailing yacht purely because I'm working. How is that captain meant to know that.
Thankfully, the IMO had a long time to think about the rules and came up with a very good fair set of rules that are simple (for most) to understand and abide by (not related to size or importance of job). Please read these rules and correct your knowledge and stop perpetuating ignorance.

Shawndear is correct, except that it's not about "right of way" but about which vessel has priority. Important distinction because the responsibility to avoid collisions always remains with both vessels. Nothing to do with tonnage, asserting rights, demanding a larger ship to give way, recreational vs. commercial, etc., but rather consistency and predictability. Much of the misconception also relies on an incorrect and potentially dangerous assumption that most professional mariners in large commercial ships are not maintaining a proper watch. The reality is that, in most cases, they can probably "see" you (and a potential collision risk) long before you "see" them, and that should therefore be the basis of your actions (and what the rules rely on) unless demonstrated otherwise obviously.

So if you are under sail in open waters and a potential risk of collision has arisen, it's not a question of a sailing vessel having a "right" to stand on, but rather having a "duty" to maintain course & speed so as to communicate predictability and reduce confusion for the commercial ship. We're not even remotely talking about a game of "chicken" here, since the duty to maintain course & speed when a potential risk of collision arises is obviously removed should an actual risk of collision come to pass. Back to the thread topic, this is where Class B AIS for recreational sailors comes into its own, since even if the commercial ship has his turned off or doesn't otherwise see you, you are able to see his AIS signal and are thus able to easily call him up long before there's a problem. This is obviously consistent with the overall purpose of the Colregs to avoid collision.

No need to create another s***t-storm over this since different sailors will reasonably make different judgments about the timing & nature of these events in practice, and much depends on the type of waters and amount of congestion. But the basic principles work well in all scenarios and to every type of vessel. Besides, there are plenty of other threads on this topic when it comes to s***t-storms. If you want a better analysis than I can possibly provide, look for threads where Jackdale, Dockhead, a few seasoned big ship captains (forgot their handles) and other more experienced mariners provide helpful analysis of theory combined with practice.

[Paul Elliott]

Originally Posted by svinshallah

A Class A RECEIVER? I know that there are Class A and Class B transponders, but I can't see that it makes a difference for a receiver.

It doesn't, at least for any receiver that isn't quite old.

Way back in the mists of time there were some AIS receivers that didn't decode class-B signals because Class-B hadn't been standardized yet and the receiver discarded any messages it didn't recognize. The early NASA "AIS Radar" and "Black Box" receivers behaved this way, but NASA quickly updated the design once the Class-B standard had stabilized. Other early AIS receivers decoded unrecognized messages and so properly received Class-B from day-one.

[El Pinguino]

Originally Posted by Paul Elliott

.................
And commenting on another issue that has been raised here: being lectured to turn off our Class-B transmissions when in a busy harbor or in the slip.

I believe that this is a completely wrong-headed way to solve the problem. If I am in a slip then I am not in the way of a passing ship. They should adjust their display and alarms appropriately. If I am on the water and in the way, the ship should want to know about my being there. Or, should I haul down my radar reflector, and cover my boat in radar-stealth screening? How about my running lights? Should I turn those off so as not to distract the ship's watch?

The solution to AIS target-overload is proper AIS alarm processing and target filtering, and proper training of the bridge crew. If the display systems aren't adequately designed then they need to be improved. But I'm not going to turn off my AIS while we wait for this to happen.

Not lecturing.... just expressing a point of view.

Consider for example a port like Hobart where arriving ships pass within a mile of reasonably large concentrations of yachts.
You have a bridge team of pilot ( unless the master is 'exempt' in which case you don't have a pilot), master, watchkeeper, and a man on the wheel.
Your AIS via your ECDIS a radar is set to give you audible alarms of any CPA's less than one mile.
So now, when you need all your concentration, this lot decide to advise you of 20 or more 'risks of collision' all of which are snug in their slips. So you have lost your watchkeeper who has gone into alarm canceling mode. The desire to take to such equipment with a fire axe can be quite strong at times like this but now it seems we have the ability to filter out all class B. Hmmmm, that seems like a good idea, lets make that SOP on arrival in all ports...... pity about the class B who are actually out and about and who would benefit from being seen in harbour approaches.

Filter out stationary targets? Bad luck about the bloke becalmed right on your track in the evening gloom.

This is still worth a read... Panbo: The Marine Electronics Hub: Class B AIS filtering, the word from Dr. Norris

... especially this bit
' For this reason, especially in areas that are crowded with small craft but that also have appreciable shipping movements - such as in the Solent area of the UK - it could well be the case that any activation of Class B targets will cause almost constant activation of the Closest Point of Approach (CPA) alarm on the ship - continually distracting the navigating officer/pilot. A 1.0 NM CPA may be appropriate for ship-to-ship encounters in such an area, but many small craft skippers will be quite happy approaching ships at very much closer distances. Therefore, filtering of all AIS Class B targets, together with preventing their activation, may be the appropriate strategy in such areas to avoid possibly dangerous alarm distraction of the bridge team.'

Hmmmm 'dangerous alarm distraction'... I rather like that.

Reduce unnecessary AIS transmissions ... reduce the risk of people filtering class B as a matter of course.

[SV DestinyAscen]

Reading the posts - I think the best approach is to minimize unnecessary transmissions, software update so that anchored/stationary transmissions get filtered somehow - and encourage best practice preventing class B filters from being ON without some level of periodic manual activation.

[Paul Elliott]

El Pinguino, I understand your point, I really do, and in the short term having berthed boats turn off their transponders would reduce the clutter. I turn mine off for just that reason.

But some people are also complaining that we are running Class-B while we are underway in the harbor -- apparently we are cluttering the plotter displays on the big ships.

You say this:

Your AIS via your ECDIS a radar is set to give you audible alarms of any CPA's less than one mile.

And there's your problem.

The proper solution to all this is not to disable Class-B transmissions, but for the ships to not be running "at sea" AIS alarm configurations in the harbor. There is no good reason for watchstanders to have to disable individual AIS target alarms under these conditions. If the software doesn't provide for a reasonable alarm setting then the software needs to be improved.

[Littlechay]

Originally Posted by Exile

Apparently many AIS systems are tied into instruments or gps w/o separate switches to turn on/off.

It is legal to turn off AIS class B and for this reason most class B transceivers have a silent mode built in (RTFM its in the menus); therefore it matters not whether the AIS is tied into other instruments or not.

[kazo]

edifying and entertaining from a newbie perspective...