What price to get excited about AIS?

[Poly]

Originally Posted by 9D280

Most of us ribbers have the plotter by the wheel. It's mostly only the Redbay guys can park theirs below deck! (Which is where the NASA "box" has it's uses on a RIB). If I;m looking to receive only, for not a lot more money then the AIS reciever, I can upgrade my radio & get DSC on the plotter as well.



...which is around 500L of fuel at marina prices, and comes back to Malthouse's original Q - How cheap does it need to be before you'll buy one?


I'm going to chuck this in as a thought in case any of the electronics manufacturers are out there: Plotter with a VHF anenna connection on the back. For the cost of a bit of added known technology (i.e.relatively small development costs), the plotter has the AIS reception built in. On a small open boat, the reduction in wiring & hardware will not only free up some space, but also improve system reliability as you don't need another NMEA talker in the bus with a few more connectors to get corroded......

I suppose taking that to it's ultimate conclusion, maybe a SW antenna connector as well - then you could get Navtex on screen too!

Standard Horizon do a system in the US which is a full VHF radio (2 way) with a plotter built in - that would presumably make what you suggest trivial (i.e. 99% software) if it is not already done. Sadly its not licensed in the EU,

[Channel Ribs]

Originally Posted by 9D280

Plotter with a VHF anenna connection on the back. For the cost of a bit of added known technology (i.e.relatively small development costs), the plotter has the AIS reception built in.

As I hinted at in my opening post, marine electronics manufacturers are not quick to develop new technologies. By develop I do not mean invent, but rather apply.

It makes no sense, but that is my experience.

[Poly]

Originally Posted by MikeCC

Standard showed their AIS-inclusive VHF radios at London. Indications on RRP look good, so discounted price will be OK. They aren't transponders though, just a receive unit. They have mini AIS display on the screen and you can scroll round them to pick up MMSI and call up directly.

I've just had a look on their US site - and it does look good (price in the states seems to be about $170 more than the equivalent radio without AIS... so I would guess you should be able to get one for something like 300 GBP here).

That feature of being able to find the ship off your starboard bow's MMSI and DSC call could justify the AIS premium. Can you do that if you have a suitable radio and plotter with AIS input? i.e. can you click on a ship displayed on the plotter and have it feed the MMSI back to the radio to initiate the call?

[Leapy]

Originally Posted by Knot Yet

Leapy - we have a 550s and have done exactly as Duck Witch (Welcome to RIBnet ) details above - works a treat and we felt it was money well spent

Jean...does that mean that if I have one of THESE then the existing Icom VHF radio aerial feeds it (as well as the radio) and then the AIS unit feeds the Garmin 550s?

How does the AIS connect to the 550? Is there a connector already there?

Is it really as simple as feed the AIS 12v, the GPS aerial input and connect it up to the 550 and away you go?

[Knot Yet]

Hi Leapy

We have one of these:

http://www.marine-super-store.com/po...artno=99119713

connected to the 550s - so the following is based on the NASA AIS ENGINE 2 ( It does look as if your one doesn't need a different aerial which is much easier for installing - but it is a lot more money so might be worth checking on what the differences are)

The AIS Engine needs a separate aerial to our fixed VHF radio (recommended set up) - it connects to the NMEA input on the Garmin cable - this is a case of wiring up as opposed to connecting together - if that makes sense!!

It is very simple - honest - but fiddly:

1. New aerial required which needs to be 1m away from existing aerial and 3 metres from the location of the AIS box - we added a T bar to the top of the A frame

2. 12v feed for the AIS

3. Wire AIS into Garmin cable through the NMEA input

4. Optional speaker for warning beebs

5. Place unit in waterproof container as the AIS units doesn't like the wet

Pretty sure that was it

J

[jwalker]

And set Garmin to high speed input?

[MikeCC]

Originally Posted by 9D280

Most of us ribbers have the plotter by the wheel. It's mostly only the Redbay guys can park theirs below deck!

Yeah, OK - but there are a few rag & stick types in disguise on here as well!

Originally Posted by 9D280

I'm going to chuck this in as a thought in case any of the electronics manufacturers are out there: Plotter with a VHF anenna connection on the back. For the cost of a bit of added known technology (i.e.relatively small development costs), the plotter has the AIS reception built in.

There is a small plotter on the market which does that, but not a mainstream brand.

[Knot Yet]

Originally Posted by jwalker

And set Garmin to high speed input?

Not sure - I don't remember doing so - but that does'nt mean I didn't

[Channel Ribs]

Originally Posted by Polwart

That feature of being able to find the ship off your starboard bow's MMSI and DSC call could justify the AIS premium. Can you do that if you have a suitable radio and plotter with AIS input?

You need a two way connection between compatible devices, but the examples given here would work.

And yes Jean, you would have had to change the data settings when you plugged AIS into the NMEA input; so easy I am not surprised you do not recall it.

[GJ0KYZ]

My Raymarine E80 had MARPA, AIS and Navtex. They're all pretty useful. AIS data can be plotted on screen next to the ship's icon. Also, the ship's track can be shown via AIS as well as those of all moving non-AIS enabled vessels (via MARPA, which needs a special compass by the way). I still think that radar's the most useful thing I have on my boat, after my ETec that is.

[Erin]

Originally Posted by GJ0KYZ

I still think that radar's the most useful thing I have on my boat, after my ETec that is.

That's interesting. I've been wondering about upgrading my Garmin system with the radar unit, but was struggling to justify the cost. Do you find you're out in conditions when you need it, or is it more of an interesting luxury?

[GJ0KYZ]

Originally Posted by Erin

Do you find you're out in conditions when you need it, or is it more of an interesting luxury?

No, I've relied on it at least a couple of times when the fog has been really thick. We followed the yachts to Guernsey in last year's race. Off Sark the visibilty was less than 200ft but the radar showed multiple bogeys all over the place and we were able to keep going. The radar image can be overlayed on the chart plotter to help differentiate rocks from stationary vessels. This feature doesn't work too well at high speed because for some strange reason the refresh rate of the radar is faster than that of the chartplotter. I'm sure this glitch has been addressed on the new Garmin models or maybe I'm doing something wrong.

I don't know where you're based; my boat's in St. Helier. If you see me out and about give me a shout and you can have a look at the gear before you buy if you like.

[Channel Ribs]

Originally Posted by GJ0KYZ

This feature doesn't work too well at high speed because for some strange reason the refresh rate of the radar is faster than that of the chartplotter.

Which model do you have?

I would be quite happy to check through the settings the next time I am over.

[smartcom]

Note that the NASA AIS unit still does not monitor both channels simultaneously, though the Mk 3 now includes support for all AIS messages, which was not the case previously. From my AIS tests for the product review in December's Practical Boat Owner, the NASA unit was not a good performer, partly due to not receiving both channels in parallel, and also because you get what you pay for - great value for money, but you aren't paying very much so the performance won't be that good.

In my opinion it is worth going for a transponder if possible - I'd feel much happier if I was in a RIB in a shipping area if I knew that I would be popping up on the radar/ECDIS system of ships in the area - I can see ships easily, but they can't necessarily see me.

Note that some plotters (e.g. Raymarine) allow either NAVTEX or AIS input, not both - but I'd go for AIS and have a seperate NAVTEX display.

For the antenna, you can use your existing VHF antenna - splitters are available for both AIS receivers and transponders - but obviously you won't receive or transmit any AIS data when talking on the radio.

Tim

[Channel Ribs]

Originally Posted by smartcom

... and also because you get what you pay for - great value for money, but you aren't paying very much so the performance won't be that good.

True, and the Comar dual channel one is only about 170.00 so the "step up" is not that huge.

But the point is - how cheap does it have to be for various cruising areas?

[Poly]

Originally Posted by smartcom

Note that the NASA AIS unit still does not monitor both channels simultaneously, though the Mk 3 now includes support for all AIS messages, which was not the case previously. From my AIS tests for the product review in December's Practical Boat Owner, the NASA unit was not a good performer,

in real terms how much does no parallel reception actually matter? did you actually get real circumstances where vessels were consistently missing from the NASA screen that showed on others simultaneously using identical arials etc.?

but you aren't paying very much so the performance won't be that good.

that argument doesn't always stack up and I would certainly expect that price is not a criteria for assessing performance (unless value for money) when someone rights magazine reviews.

In my opinion it is worth going for a transponder if possible - I'd feel much happier if I was in a RIB in a shipping area if I knew that I would be popping up on the radar/ECDIS system of ships in the area - I can see ships easily, but they can't necessarily see me.

mmmm.... does that give a FALSE sense of security? my understanding is that (1) in busy waters the 'leisure AIS traffic' will be ignored to provide adequate space for 'commercial AIS traffic' - I'm not sure if you get a warning to highlight this is likely to be a problem (2) as I understand it not all large commercial vessels display the AIS data in an easy to read chartplotter screen - some (many?) simply list them in a table format. Does vessel XXX at WWW and NNNN heading BBBB at KKKK knots realy mean the skipper "sees" you - or just that he has a way of finding you if he tried to. Before "Zabaglioni" jumps to the defence of all commercial skippers - thats not a criticism of merchant seamen - its a comment on the expectation of leisure sailors that by transmitting a little burst of data every few seconds that they become visible or invincible.

[Channel Ribs]

Originally Posted by Polwart

In real terms how much does no parallel reception actually matter?

You will get less detailed data and some info is not broadcast that often and without a true parallel receiver there is a greater chance of missing the longer packet of info.

So in real terms you still get the important stuff - location, speed and heading. But in crowded waters you might have to wait for a new vessel's info to be fully populated.

Having said that I have not tested the new Mk3 NASA yet, so their software may be able to deal with this problem better now.

[Poly]

Originally Posted by malthouse

You will get less detailed data and some info is not broadcast that often and without a true parallel receiver there is a greater chance of missing the longer packet of info.

So in real terms you still get the important stuff - location, speed and heading. But in crowded waters you might have to wait for a new vessel's info to be fully populated.

Having said that I have not tested the new Mk3 NASA yet, so their software may be able to deal with this problem better now.

Ah but Malthouse - thats not what I asked! I asked 'in real terms' not the on paper answer which I understood. What I want to know is has anyone put this to the test (as you might expect a magazine reviewer to do before criticising it?) in realistic real life circumstances, and seen a significant issue. How crowded does it need to be - are we talking cowes week or the dover straights? Does it really cause a problem if you have to wait an extra minute or two to get 'full data' or see a vessel 5,10,15 nm away - bearing in mind that you are unlikely to be going full tilt in 'crowded waters'? And for the 99% of the waters which are never likely to be classified as 'crowded' is there an issue at all?

Edit: I have no axe to grind here and have never used a NASA AIS unit; but for AIS to gain widespread acceptance in the leisure boat community I think it needs people like NASA willing to push the price down, if necessary by skimming off any unnecessary functionality.

[Channel Ribs]

Originally Posted by Polwart

How crowded does it need to be - are we talking cowes week or the dover straights? Does it really cause a problem if you have to wait an extra minute or two to get 'full data' or see a vessel 5,10,15 nm away...

I have used both types in the Thames estuary, which is pretty crowded I think you will agree. Both worked quite well enough to be of benefit, but the NASA Mk1 did not report nearly as much detail the first time it picked up a vessel.

The only time I got confused with the NASA was when I saw a craft doing 70 knots in the area of Gillingham.

[Poly]

Originally Posted by malthouse

I have used both types in the Thames estuary, which is pretty crowded I think you will agree. Both worked quite well enough to be of benefit, but the NASA Mk1 did not report nearly as much detail the first time it picked up a vessel.

yes I guess that was my point - it works - it shows the vessels in a reasonably busy area. I think someone reading Tim's review may get the impression that actually the NASA unit doesn't really do the job.

The only time I got confused with the NASA was when I saw a craft doing 70 knots in the area of Gillingham.

Was that the NASA or the output on the other craft though. i guess that is a failing on AIS in general - you rely on the transmitting vessel sending the correct info.