Which AIS engine and plotter?

[toad]

A quick question for the experts, I have just been given a NASA AIS with no plugs or aerial ,the plugs I can sort but I do not have a small vhf aerial handy. I do have a nice little uhf aerial and mount on the shelf, I know its not perfect but as its not transmitting will it work good enough to see if I can get on with it. If I like it I will set it up properly but would like to test it first.

 

[john_morris_uk]

A quick question for the experts, I have just been given a NASA AIS with no plugs or aerial ,the plugs I can sort but I do not have a small vhf aerial handy. I do have a nice little uhf aerial and mount on the shelf, I know its not perfect but as its not transmitting will it work good enough to see if I can get on with it. If I like it I will set it up properly but would like to test it first.

For receive only, it will almost probably put enough signal into the box to test it. If it doesn't you could try a bit of wire. (Make it 18 or 19 inches long.) A proper antenna will be even better when you come to use it in anger.

 

[DJE]

Just been through this - see thread linked below. IMHO the AIS display in Opencpn is better than anything else I've seen. So I went with an Emtrak transponder linked to on old laptop with Opencpn and charts on a USB stick from Visit My Harbour. Now considering a windows tablet to replace the laptop to save space and power. I used a Digital Yacht NMEA to USB converter to connect the laptop as Emtrack don't recomend using the USB interface on the transponder long term. So far it all does what it says on the tin.

http://www.ybw.com/forums/showthread.php?452467-Which-AIS-Transponder

 

[dom]

A quick question for the experts, I have just been given a NASA AIS with no plugs or aerial ,the plugs I can sort but I do not have a small vhf aerial handy. I do have a nice little uhf aerial and mount on the shelf, I know its not perfect but as its not transmitting will it work good enough to see if I can get on with it. If I like it I will set it up properly but would like to test it first.

Any aerial tuned to around 162 MHz will do, i.e. almost all VHF aerials. So why not just temporarily unplug yours from your VHF and stick it into your new NASA box? You can flip it back whenever you like, or perhaps use a h/h VHF for a while?

 

[jonjo]

Just been through this - see thread linked below. IMHO the AIS display in Opencpn is better than anything else I've seen.

However once you add in a depleted main battery that won't charge to laptop with 5% battery life left, rain, spray soaked clothing, darkness, some angry overfalls and a small coaster trying to round the headland at the same time and it is no longer clear which is better.

 

[GHA]

However once you add in a depleted main battery that won't charge to laptop with 5% battery life left, rain, spray soaked clothing, darkness, some angry overfalls and a small coaster trying to round the headland at the same time and it is no longer clear which is better.

Android Opencpn app works a treat on an xperia tablet. Just did uk algarve in some occasionally less than beautiful conditions, full marks. Though you still need to get the data out on AIS, not hard either with a Raspberry Pi and low current draw. Not for everyone but definitely an option. And the Opencpn ais display really is very good.

 

[RichardS]

Just last night I upgraded my VesperMarine XB8000 with the new firmware and I'm very impressed, lots of new features including a demo mode so you can run through a real time simulation which includes a MOB, an AIS beaconed-shoal, a fixed refueling station and lots of boats approaching from all angles. There are some technical NMEA and Seatalk options which are a bit beyond me ........ but the MOB function and the anchor watch are both completely new.

The anchor watch function is very inpressive and nicely implemented. I will use this rather than my Android app as it's so easy to use and does not drain the tablet's batteries as much as the app as it receives all the GPS info from the XB8000 and it's the GPS which uses a lot of power. You can even sleep the tablet so it's using virtually no battery but if your anchor drags by any more than you amount you have preset then the XB8000 will wake up the tablet and sound to alarm.

Richard

 

[LadyInBed]

Re Plotter, I would advise that you first research which cartography suits you best - presentation, colour, cartridge coverage, price. Then choose the plotter that will take it.
Re AIS, I think that one with wifi is the way forward. You never know, you might want to put cartography on a Tablet at some time in the future :eagerness:

 

[sailorman]

However once you add in a depleted main battery that won't charge to laptop with 5% battery life left, rain, spray soaked clothing, darkness, some angry overfalls and a small coaster trying to round the headland at the same time and it is no longer clear which is better.

Our first 15 yrs of sailing was without VHF,Decca or L/R, we coped ok

 

[toad]

Any aerial tuned to around 162 MHz will do, i.e. almost all VHF aerials. So why not just temporarily unplug yours from your VHF and stick it into your new NASA box? You can flip it back whenever you like, or perhaps use a h/h VHF for a while?

Its a bit of a pig to get to the back of the radio but thinking about it I suppose I could use the h/h aerial.

 

[jakeroyd]

Not a plotter I know, but have you considered a Standard Horizon GX2200E ?
This combines a DSC radio, GPS and an 2 band AIS receiver together.
Presents AIS data on the familiar target format and does provide a direct DSC call to specific MMSI.

 

[RobF]

I'm currently investigating the same options so am following this thread with interest.

I'm not entirely convinced about the Transceiver but do think a Receiver would be a useful addition. The McMurdo M10 seems to have the usual features (including both NMEA protocols, USB and WiFi). I'm also thinking that a VHF splitter is a better option than a stand alone aerial - due to the height of my VHF aerial versus the height of a pushpit mounted aerial. Whilst this won't receive AIS whilst it's transmitting VHF, I don't do that much transmitting (and when I do, it's normally because I'm calling up a marina and missing an AIS transmission would be of minimal consequence). I'm therefore pondering the McMurdo M15S which has a built in splitter.

Will your existing plotter take an AIS feed and are you keen to upgrade this regardless?

 

[DJE]

On the subject of silence (do not transmit) switches for class B transponders, I have seen up to 120 targets in the solent some weekends this season. So if we don't switch off in crowded areas I wonder how long it will be before the system is overloaded.

 

[dom]

On the subject of silence (do not transmit) switches for class B transponders, I have seen up to 120 targets in the solent some weekends this season. So if we don't switch off in crowded areas I wonder how long it will be before the system is overloaded.

Some space yet I'd imagine -- take a look off Singapore this w/e!

 

[RichardS]

I'm currently investigating the same options so am following this thread with interest.

I'm not entirely convinced about the Transceiver but do think a Receiver would be a useful addition. The McMurdo M10 seems to have the usual features (including both NMEA protocols, USB and WiFi). I'm also thinking that a VHF splitter is a better option than a stand alone aerial - due to the height of my VHF aerial versus the height of a pushpit mounted aerial. Whilst this won't receive AIS whilst it's transmitting VHF, I don't do that much transmitting (and when I do, it's normally because I'm calling up a marina and missing an AIS transmission would be of minimal consequence). I'm therefore pondering the McMurdo M15S which has a built in splitter.

Tranceivers are more expensive of course ..... but the fitting and connecting-up aspect is almost exactly the same so while you're at it, why not go the full monty. With the transceiver you do have to site the GPS mushroom (unless it's built-in to some models?) but I tried just throwing mine onto the locker floor next to the AIS unit and it locks on instantly. These things are so sensitive these days that you could chuck it in the bilges and it would come up smelling of roses.

I used a separate Vesper Marine active splitter with my XB8000 as that was also a doddle to connect up at the same time as all it needs is the power connection which I just piggy-backed from the transceiver. You then just plug in the cables. A two minute job but if the McMurdo has a built in splitter, which will be active I'm sure, then that's no job at all.

Don't worry about AIS signals ....... they are intermittent anyway so you would have to be talking on the VHF for ages before you seriously began to degrade the AIS information.

Richard

 

[RichardS]

On the subject of silence (do not transmit) switches for class B transponders, I have seen up to 120 targets in the solent some weekends this season. So if we don't switch off in crowded areas I wonder how long it will be before the system is overloaded.

I guess it depends what you mean by overloaded. My transceiver can process up to 600 ships simultaneously so overloading that end of the system is never going to be a problem as the outer 200 or 300 of those are probably 50 miles away.

If you mean overload at the display end, then it's all down to the display processing software and how clever it is. If you filter everything down to highlight on the screen only vessels which are 5 miles away with a CPA of 1000m and a TCPA of less than 15 minutes (or whatever works for you) then suddenly you only have to think about 2 or 3 targets and the other 150 are irrelevant.

I imagine that the display functionality will get smarter with each version that comes out.

Richard

Just an after-thought for anyone like me who has always been a bit miffed by the fact that on the AIS vessel-watching websites like Marine Traffic, the signal from all the boats would vanish a 1/4 mile from the entrance to the bay where Marina Kremik is situated. There's been this reception black-spot here ever since I fitted AIS 2 years ago.

Well I turned on my AIS last night to upgrade the software and, suddenly, my boat and the half dozen others with their AIS turned on (some are left like that all winter for some reason, even though the owners are back home in Austria) all appeared on Marine Traffic! Whoever maintains these coastal AIS stations must be installing more of them.

 

[GHA]

On the subject of silence (do not transmit) switches for class B transponders, I have seen up to 120 targets in the solent some weekends this season. So if we don't switch off in crowded areas I wonder how long it will be before the system is overloaded.

Plenty headroom in the frequencies but the software might top out. Not that it matters, in the tiny number of places in the world where there can be that many boats the ais system stops being of any real use, eyeball is the way to go.

 

[DJE]

I was thinking about bandwidth and/or time slots on the transimission frequencies.

(I can cope with the display clutter by switching off the COG predictors in Opencpn. It switches them back on itself for any targets which meet my CPA and TCPA criteria.)

 

[Sandyman]

I thought so - hence my hopeful question for guidance!

I guess I will have to find somewhere that stocks these things and go and have a look. I'm used to the Raymarine stuff and we've got Raymarine instruments so one is always hopeful that they will integrate...

That being so, may I suggest you look at Digital Yachts AIS. Ten years ago I did a lot of research before installing a plotter & AIS. Eventually went for a Raymarine C70 with Digital Yachts AIS. It has been used extensively over the years & has been superb to say the least.

PS. Could someone tell me why these things are called ''Engines'' ?

 

[GHA]

I was thinking about bandwidth and/or time slots on the transimission frequencies.

(I can cope with the display clutter by switching off the COG predictors in Opencpn. It switches them back on itself for any targets which meet my CPA and TCPA criteria.)

Not likely to be much of a problem, also class B just take whats left, IIRC.


https://mcanet.mcga.gov.uk/public/c4/solas/solas_v/Annexes/Annex17.htm
[FONT=Verdana, Arial, Helvetica, sans-serif]2.) [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]The required ship reporting capacity according to the IMO performance standard amounts to a minimum of 2000 time slots per minute (see fig. 3). The ITU Technical standard for the Universal AIS provides 4500 time slots per minute. The broadcast mode based on a principle called (S)TDMA (Self-organized Time Division Multiple Access) that allows the system to be overloaded with 400 to 500 % and still provides nearly 100% throughput for ships closer than 8 to 10 NM to each other in a ship to ship mode. In the event of system overload, only targets far away will be subject to drop out in order to give preference to targets close by, that are a primary concern for ship-to-ship operation of AIS. In practice, the capacity of the system is unlimited allowing for a great number of ships to be accommodated at the same time.[/FONT]