Class B AIS waste of money

[weavis]

Guys

Please try and be polite to each other..

treat this as a polite but firm request.

[conachair]

Originally Posted by newhaul

Well all of this solves it for me my next boat gets a class A system

Have you considered spending the money on an active radar reflector instead ?

[TheThunderbird]

My conclusion?

The TX section of a classB AIS is rather unuseful. Basically not well spent money.
Only commercial ships, fishermen and charter must have it, and accordingly a leisure yacht should behave at maximizing its ability to know about, not necessarily to be known about by others (in so far as you can be undetected, without knowing it!)

[TJ D]

Originally Posted by TheThunderbird

My conclusion?

The TX section of a classB AIS is rather unuseful. Basically not well spent money.
Only commercial ships, fishermen and charter must have it, and accordingly a leisure yacht should behave at maximizing its ability to know about, not necessarily to be known about by others (in so far as you can be undetected, without knowing it!)

I'll have to say that I respectfully, and very strongly disagree with this. I'm not being dramatic when I say that AIS is the biggest contribution to marine safety since GPS. You're missing out on a lot of benefit with a receive only unit.

From my commercial perspective, a little ARPA target is a lot less desirable than ARPA and AIS together.

From a sailing perspective, the difference in the way ships interact with you is really remarkable. Instead of relying on a marginal radar return and your lights which may or may not be visible to them, they've got some good, solid info to make their maneuvering choices.

I used to sail with a RX only unit, and we didn't see nearly the proactive steps taken by other traffic that we do now that we're transmitting.

I'm not telling you what to do, but I'm telling you with 100% certainty that if you're out cruising in areas with commercial traffic, transmitting AIS is very simply a good thing to do.

If you want to be private for some reason, most units let you go into 'silent' mode, too. Why not have it both ways?

My guess would be that if you install a TX/RX unit, you will be extremely unlikely to regret the choice.

If you're just sticking around a small area and only sailing during daylight and in good visibility, it's a different story, but if you're out doing more than that, you'll appreciate the TX as well.

TJ

[newhaul]

Originally Posted by conachair

Have you considered spending the money on an active radar reflector instead ?

I have considered the active radar reflector option however some of the areas I wish to revisit now days have rules requiring AIS on foreign pleasure vessels in their territorial waters. interestingly they are also major manufacturers of them as well .

[250224]

Originally Posted by TheThunderbird

My conclusion?

The TX section of a classB AIS is rather unuseful. Basically not well spent money.
Only commercial ships, fishermen and charter must have it, and accordingly a leisure yacht should behave at maximizing its ability to know about, not necessarily to be known about by others (in so far as you can be undetected, without knowing it!)

In areas with heavy traffic it is very helpful if other boats know about you. Why would you forgoe this? Class B AIS transmitters are not expensive nowadays and every boat cruising in such areas should have it. Of course it doesn't replace a proper look out.

Do what you want, but it is, imho, a wrong conclusion. While anecdotal in my marina more and more AIS boats are appearing (and also in the places I sail to).

[TheThunderbird]

I try to be clearer

Class A ships may switch off class B (TX) signals. It seems that they do, more and more so.

Maybe in case of real danger this exclusion may be overridden by their AIS !?

Best bet is to realize that your transmission is likely unmanaged/unreceived
Otherwise (not realizing that), and also expecting pro-active (?) maneuvers from big ships, is a really dangerous behaviour imo.

Sure, you can transmit, and behave as prudently AS IF your TX is NOT received...

All in all, a marginal help (the TX section) which cant diminish your level of watch. It almost makes for a big chunk of the total cost (by heart) and antenna installation.
In contrast, the value added by having the RX section is predominant, well defined, controllable.

Guess vs.Certainty

I mean, not always more is better (cum grano salis, ancients said)

[TJ D]

Thunderbird, have you used a TX/RX AIS, ever?

I do not think, nor do the other professionals here think that the practice of switching off class B is common on ships. Maybe SOME are doing it in congested waters, but this is not where AIS is a big benefit anyway. In a harbor, it's not the primary tool. It's not the primary tool anywhere, but in congested waters, it's just another supplement.

But out away from congested harbors, it's a very, very big help.

Nobody is counting on a ship to do anything. There's nothing dangerous about what we're talking about. What we're saying is that when you're transmitting, ships DO MUCH MORE OFTEN take avoiding action. Period.

I don't think that anybody's suggesting "Hey, I've got an AIS, so I don't need to stand a watch".

A great deal of this lies in accountability of the ship's officers. I'll give you an example.

On the way out of Dutch Harbor to the fishing grounds, we cross a major shipping lane. Prior to AIS-at night especially, a large portion, probably the majority, of ships did not act according to COLREGS. The boats would just hold their course no matter what. I run a big trawler here, there is no shipping lane special circumstance, just 2 M/V's crossing.

Radio calls were usually unanswered.

In about 2007, we stuck on our first AIS. Something magical happened. It turns out that these guys knew the rules all along! They were identified, and therefore accountable. Suddenly, all was much, much, smoother. The late adopters to AIS still carried on with the same old crap.

It is the same with our toy boats. The difference in the actions of shipping is really something.

Again, this doesn't mean that anybody's counting on it. But proper avoiding action on the part of shipping that should take it is far more common.

Trust me on this.

TJ

[Celestialsailor]

Originally Posted by TJ D

I'm not being dramatic when I say that AIS is the biggest contribution to marine safety since GPS. You're missing out on a lot of benefit with a receive only unit.
TJ

While I agree wholeheartedly with having a Tx...if...you can afford it. My AIS receiver cost me $200. A Tx is over $600. Giving that I needed to replace my magnatron in the radar as oppose to a new radar unit and building a custom Spectra watermaker and revamping many other systems on my boat and the fact that I am limited with finances, money is spread quite thin. Having an AIS receiver is miles ahead of not having anything at all.
I'm sure many other cruising enthusiast are in the same boat as I am. My main concern is being mowed down by a commercial vessel, so having the AIS with alarm is a great asset for me.

[Dockhead]

Originally Posted by TheThunderbird

I try to be clearer

Class A ships may switch off class B (TX) signals. It seems that they do, more and more so.
)

You've heard two (or was it three?) different actual commercial captains in this very thread, tell you that switching off Class "B" targets is NOT common practice on ships, and they explained to you why, too.

Why would you insist on your made-up idea of how commercial mariners think and work, even when you've heard otherwise, and straight from the horse's mouth?

Originally Posted by TheThunderbird

. . . Best bet is to realize that your transmission is likely unmanaged/unreceived
Otherwise (not realizing that), and also expecting pro-active (?) maneuvers from big ships, is a really dangerous behaviour imo.

Sure, you can transmit, and behave as prudently AS IF your TX is NOT received...

All in all, a marginal help (the TX section) which cant diminish your level of watch. It almost makes for a big chunk of the total cost (by heart) and antenna installation.
In contrast, the value added by having the RX section is predominant, well defined, controllable.

And continuing the thought --

Why would you invent a way to maneuver yourself (as if no one can see you)? When there is a right way, a way required by law?

You have no right to maneuver as if no one sees you -- it is unseamanlike and dangerous. What makes you think they don't see you, even if you're not broadcasting AIS?

The right way to do it is, on the contrary, to assume, to begin with, that they see you and are following the rules themselves. Stay out of their way to the extent you possibly can; but follow the Steering & Sailing Rules if you get into a risk of collision situation. It is what they expect and want you to do. The better they see you, the better the whole system works -- which is why the commercial mariners on here, have told you, that they would prefer it if you were broadcasting AIS.


If you've never stood on the bridge of a ship underway -- their radars do stuff that we can only dream about. With pretty rare exceptions, they see you long before you even know they are there. Assuming that they can't see you would lead to some really WAFI-like behavior, which reduces, does not increase, saftey.

[MarkJ]

Originally Posted by TJ D

I'm not telling you what to do, but I'm telling you with 100% certainty that if you're out cruising in areas with commercial traffic, transmitting AIS is very simply a good thing to do.



TJ

I would think that any anti-AIS person has not been to sea with one.

I would, now, never sail an offshore passage in a boat without AIS. Like anti-vaxers, I don't need idiots in my life.

[TheThunderbird]

I am not against AIS.

my impressions are based on what l read here (a fraction of all posts ) speaking about classA filtering classB "noise" (not my invention; % relevance unknown to me)

DH, assuming not to be seen is the best way to avoid a crash, as much as assuming that a big ship positively can/want to steer away is rather risky to me (as they can hardly do, in fact).

You dont need to communicate anything for safety, other than :

behaving according to your/their right-of-pass,
showing clearly what you are doing (e.g. if i steer away, i do it by 30° and not 7°..),
giving up your own rights as soon as you see that there is someone inconsiderate out there

But, as l read just a fraction of 14pages of posts:
I thank TJ for tipping the balance of my overall impressions;
And praise his note that Accountability (being identified by AIS) is a big factor in big ships behaviour

I am no crusader, and plan to install AIS soon, and still have no conclusive idea about the RX v RX/TX comparison.

But my point remains: transmitting can be useful :-P, but transmitting and thereby behaving AS IF anyone sees you, that sounds overly risky to me.

My way, Sirs.

[MarkJ]

Originally Posted by TheThunderbird

my impressions ....

I rest my case.



G o t o S e a.




Mark

[CarlF]

+1 for MarkJ

Question 1 - Is there anyone reading this thread who has an AIS tranceiver who does not keep it turned on anywhere commercial ships are a collision risk? Including a crowded harbor?

Anyone? Anyone?

Question 2 - Is there anyone with an AIS transceiver who doesn't think it was a great purchase?

Anyone? Anyone

Question 3 - And has anyone been on a bridge of a large commerical ship where they saw that the AIS reciever was set to filter out ALL class B.

Anyone? Anyone?

The clutter argument is a good indicator that the person doesn't actually know anything about AIS. Intelligent filtering is one of the great benefits of a good AIS receiver. My Vesper AIS is set to highlight only boats underway with a CPA of less than 1 mile (2 miles offshore). Even in the most crowded harbor, there is never any "clutter".

If I want to see clutter, I can always look at my radar

[daletournier]

I think once your have a a few miles with a class B ais after years without one you soon realize just how good they are, not just because of the shipping.

Bottom of Mindanao Philippines, underway we were boarded aggressively by one guy with 3 other bankas approaching fast. Its along story which I wont go fully into here. As I held the guy off and dealt with the situation I instructed Vicky to head down stairs and contact friends in an anchorage 5nm away to ask them to track us via ais.
Fortunately we didnt get hurt but it was nice knowing several other cruising boats were aware of the situation unfolding and knew exactly where we were.

Another eg. Sometimes anchorages in out of the way places are not charteded very well, being able to see the track of a friend going in before you which had been transmitted via his ais is another tool that helps increase safety.

The most important one for me is there has been one occasion in quite heavy weather when its been easier for the ship to alter course than me on a small getting hammered sailing vessel due to the weather, the captain was more than happy to make life easier for me and alter course, this only can happen do you to him understanding my course exactly.

My new boat only has a recieve type AIS, I just purchased a vesper 8000 class B which I haven't installed yet, experience upto date tells me this is not a waste of money.




Sent from my vivo Y35 using Cruisers Sailing Forum mobile app