Radar or Not ?

[DotDun]

Originally Posted by conachair

That just confuses me. As said before, why not have a piece of kit onboard which costs less than a shiney jacket and provides a lot of very accurate useful info?

What's not to like??

I do like that theory of AIS, as we've been discussing, the implementation has some ugliness. Fortunately, places I frequent don't have a lot of big traffic, even Miami is calm IMO.

I've been keeping my eye on them, but like I said I've spent lots of $$ to beta new stuff and it's getting old. I do believe that a receiver only is just a sexy toy. So, the utopia Class B AIS transceiver would be:

1) Built into a nice fixed mount VHF radio utilizing 1 antenna (ICOM 504?)
2) Interface with NMEA2000
3) Utilize the N2K GPS already installed
4) Click on a target on the chart plotter and it prepares the DSC call on the VHF
5) Whole package <$1000

ICOM, SH are you listening????

[xymotic]

Originally Posted by DotDun

ICOM, SH are you listening????

I'm not an Electrical engineer by any stretch, but I think pumping a bunch of watts into an antenna AND then wanting it to receive with good sensitivity simultaneously would be 'problematic' to say the least. at least until they do away with analog VHF.

[barnakiel]

Originally Posted by s/v Jedi

I think a good point for AIS hasn't been discussed yet... in contrast to radar, AIS can "see" behind land features like a cape, mountain etc. This means that AIS can warn for collision while even the best ARPA stays silent.

I think there was a collision in Asia where AIS warning was ignored and ARPA stayed quiet? anybody know the details?

ciao!
Nick.

Yep. If the equipment is so designed, no need to keep on staring at the screen.

Have toys, know how to use them, and use them, AND keep eyes on the road! ""

b.

[conachair]

Originally Posted by DotDun

......... even Miami is calm IMO.
......... I do believe that a receiver only is just a sexy toy. ......

Fair call. Looks like every big motor boat is in a marina in Fort Lauderdale !

Live Ships Map - AIS - Vessel Traffic and Positions
Zoom into the english channel, imagine crossing that, for not much money you can get a really sexy toy which will show all that lot

[IslandHopper]

Bollocks, comparing Radar to AIS is just moronic, AIS was never aimed to replace or compare to Radar, they are two different tools serving a separate purpose......

[FlyingCloud1937]

Originally Posted by conachair

Fair call. Looks like every big motor boat is in a marina in Fort Lauderdale !

Live Ships Map - AIS - Vessel Traffic and Positions
Zoom into the english channel, imagine crossing that, for not much money you can get a really sexy toy which will show all that lot

Just imagine less then 20% of the actual boats on the water are reporting with AIS, and you're crossing the english channel in fog without a radar.

NOW that's not so sexy...it's just plain hair raising.

L

[conachair]

Originally Posted by FlyingCloud1937

Just imagine less then 20% of the actual boats on the water are reporting with AIS, and you're crossing the english channel in fog without a radar.

NOW that's not so sexy...it's just plain hair raising.

L

Crossing with niether is hair raising even in perfect viz. Imagine crossing a freeway on a donkey. All the ones you really need to worry about are transmitting. Everything else is going at 90 deg to them, same as you. For those who can't afford anything else ais helps enormously.

Strangely people have been sailing here for many centuries without radar and not all of them died.

[barnakiel]

Originally Posted by IslandHopper

[COLOR=black][FONT=Verdana]Bollocks, comparing Radar to AIS is just moronic,(...)

;-)

Yes. But it is also:

1) popcorn,
2) getting us from #1 to #230,
3) more popcorn.

;-)

b.

[DotDun]

Originally Posted by conachair

..... All the ones you really need to worry about are transmitting. Everything else is going at 90 deg to them, same as you. For those who can't afford anything else ais helps enormously.

IMO, this is THE major problem with AIS......believing that a collision with a vessel under 300T is nothing "to worry about"! Hence, AIS "helps enormously".

It's like going to a nuclear war carrying only a machete.

I wonder what percentage of on-water collisions involve a vessel over 300T? I'll bet far less than 1%.

[DotDun]

Originally Posted by conachair

Strangely people have been sailing here for many centuries without radar and not all of them died.

Predication: Putting all your trust in AIS will change this stat!

There's a difference between having no tools and putting too much trust in the wrong tool! Humans are funny that way!

Accident Report: "It's not my fault, I saw nothing on AIS prior to the collision!"

[conachair]

Originally Posted by DotDun

IMO, this is THE major problem with AIS......believing that a collision with a vessel under 300T is nothing "to worry about"! Hence, AIS "helps enormously".

It's like going to a nuclear war carrying only a machete.

I wonder what percentage of on-water collisions involve a vessel over 300T? I'll bet far less than 1%.

Read the post.

It said "in perfect viz".

The "helps enormously" comes from experience. instead of trying to guess which of the line of ships you are going top pass between (usually 4th or 5th, or 5th and 6th) you can easily tell. A lot less stressful

Try it before passing judgement.

[conachair]

Originally Posted by DotDun

Predication: Putting all your trust in AIS will change this stat!

Who said anything like that???? That's comletely dangerously nuts!!!!!!!! I would advise against ever considering to get on a boat with anyone who thinks like that. Death wish.

Rule 5:
"every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision."

[Greggegner]

With some exceptions AIS is a early warning to big ships in the area. It is good to understand their course. Some smaller boats have AIS but not enough to rely on. We can all paint scenarios where AIS or radar is best. The fact is that both are useful but they don't replace looking around. We had a serious collodion between a trolling 20' foot fishing boat and a 40' motor yacht on a clear day. This was avoidable. Currently I only have radar, my reasoning for getting radar first was fog and that most boats don't have AIS. I know I may never see the 15' boat but I will see the 35' or bigger.

[DotDun]

Originally Posted by DotDun

Predication: Putting all your trust in AIS will change this stat!

There's a difference between having no tools and putting too much trust in the wrong tool! Humans are funny that way!

Accident Report: "It's not my fault, I saw nothing on AIS prior to the collision!"

Originally Posted by conachair

Who said anything like that???? That's comletely dangerously nuts!!!!!!!! I would advise against ever considering to get on a boat with anyone who thinks like that. Death wish.

Rule 5:
"every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision."

Go back and read the OP!

1) Do you believe he has the same understanding of the context in which AIS is useful?

2) Do you think by touting how wonderful AIS is in showing vessels over 300T, and stating one doesn't need to worry about the rest, the OP is going realize the useful of radar?

Please characterize AIS for it's place in the bag of navigational tricks. Don't oversell it, some believe everything they read on the Internet.

[DotDun]

Originally Posted by conachair

Who said anything like that???? That's comletely dangerously nuts!!!!!!!! I would advise against ever considering to get on a boat with anyone who thinks like that. Death wish.

The problem is you don't have to be on that boat to get hurt, this person can hurt you no matter what boat you are on.