By Russ, on August 24th, 2009
I applaud Raymarine for having brought this unit out earlier this year, it is good product marketing and market positioning (pun intended:-)
But if you already have a reasonably sophisticated set up, and already have AIS, is it worth spending £800+ to upgrade to this unit?
Here is my take on the list of features for the AIS500:
| Feature |
Comment |
| * Class B AIS Receive & Transmit |
Good – and so do all the competition at this level |
| * Dual Channel AIS Monitoring Ability |
Good – and so do all the competition at this level |
| * Targets displayed on chart and radar screens |
Clever – but I normally overlay radar on the chart plotter or display AIS targets on the chart rather than the radar which could be very confusing if not misleading due to the different methods of target acquisition |
|
* LED Status Indicator
|
Good – Surprising omission on so many marine electronics and very annoying when there is no status light and you are troubleshooting.
See my posting here on the RaymarineAIS250 |
| * NMEA 0183 – Compatibility with Raymarine A, C, E and G Series |
Good – the great majority of Raymarine users must be on C series (or lower) still. |
| * Buddy Tracking via Raymarine MFD – Distinguish favourite targets (MMSIs) from others by adding to favourite list |
Clever – but is this really needed – oh ok could stave off boredom in some situations to switch between “favourites” and “all” targets. In between calling your buddy on the radio… |
| * Silent Mode – Turn off transmit function during tournaments or races if you do not wish to be seen. |
Good – But only if you expect to be sailing in regions where piracy is possible – not really a problem in the Solent – yet!
I did refer to this as a good thing in my posting here:-) |
| |
|
| * Built-in NMEA multiplexor |
Not Good – I have a principle of using separate dedicated pieces of electronics instead of multifunction devices ion this situation. A faulty multiplexor can take down the whole backbone and all links between devices I would not want to troubleshoot that with a device that was doping so much else as well.
See my posting here on multiplexors. |
| * VHF Splitter – No need to buy a separate antenna. Utilize your existing VHF antenna and cable. |
Not good – don’t use splitters on your VHF cable!. keep the radio and its aerial as separate as possible. Yes I know that DSC has meant connecting the VHF to the NMEA circuit – but just don’t mess with the VHF aerial. This is a critical lifeline. Install a separate VHF aerial for AIS on the pushpit IMHO. |
| * Includes dedicated external GPS antenna (16 channels) |
Not good – as per comment above. Keep the GPS separate, you probably already have one, get another one for backup don’t get one built in to another multifunction device. |
|
* Configure via PC Software
* Software upgradeable through PC and RS232
|
Ok – but why use serial connections and then very probably a serial to USB convertor when you can use high speed USB. Most modern laptops don’t even have serial ports
See my posting here on serial / USB convertors |
I last did a quick survey of transponders (or are they transceivers) in June 2008, but I have held off updating this since I believe that we can expect another revolution in AIS for small boats in the next 6 months.
On that basis I would not buy the AIS500 now, if you already have AIS – if you don?t – then it is a very capable unit with the benefit of a back up GPS.
If you already have AIS and you want to spend £800 buy Raymarine shares, if you made 30% profit when Garmin buy them, that would be an extra £240 to spend on the next generation AIS – then again shares can go down as well as up:-)
By Russ, on October 13th, 2008
If you have read up on AIS including posts here on this blog you may recall that AIS uses very short bursts of high speed data on two VHF channels in the marine band. The two frequencies used are 161.975 (Marine ch 87) and 162.025 (ch 88) MHz. Ships broadcast their identity, position, course, speed and destination so that other ships can take account of their movements.
Using a low cost radio scanner tuned to one or other of these channels and ShipPlotter software running on your PC, you will be able to see a radar-like real-time map of all the large ships manoeuvering in your area together with information about their destination, estimated time of arrival and even the dimensions of each vessel.
ShipPlotter decodes the AIS digital signals from each ship using the sound card in your PC. You need a suitable VHF band radio receiver tuned to one of the two AIS channels. The program decodes the received digital data and displays it in a variety of formats.
Well it seems I had forgotten about the AIS site that is run by a group of “ShipPlotter” enthusiasts. The ShipAIS site has a strong focus on the Liverpool and Irish sea area..but there are enthusiasts all over the place! and so an entire map of the UK can be derived showing ship movements all around the UK coast.
Using this site you can even search for specific boats. Take the newly launched super yacht Elandess for example …here you can see it leaving the UK waters heading for Gibraltar on 13 Sept – at full speed of 16Kts.
There is an interesting forum attached to this site too…have a look at. http://forum.shipais.com/ which has plenty of AIS related debate, links and photos too.
By Russ, on October 10th, 2008
Earlier this year I commended Martin Waller in East Anglia for his live AIS site – well now we have a similar site based right on the English Channel. This site is a fantastic aid for all English Channel sailors and power boaters Saltdean AIS.
Here you can see data being updated every 5 mins for the shipping transmitting AIS data in the English Channel. You can even get detailed charts for many of the major ports along the Channel.
You can see how clearly the Traffic Separation Scheme is marked by the traffic and in the following chart you can also see the very congested display of ships name – a clearer table display can be seen on the Saltdean AIS site itself.
The author also provide a KMZ file that you van download and display using Google Earth.
What a great job! This shows off so many new technologies both hardware and software, in one fell swoop …and its useful for mariners too!
By Russ, on August 9th, 2008
It is annoying that the Raymarine C and E series which have an AIS interface have no displays to show whether AIS is actually working but has no data to display.
Both these displays simply say “No AIS” in the top right hand status corners of the screen. From the software developers point of view they probably would say indignantly that this language is consistent with the message displayed before the GPS Fix is obtained – in other words “No Fix”.
But the difference is this:
1. “No Fix” means the GPS is still obtaining satellite and the chartplotter is calculating the position of the boat. After few minutes if no fix is still displayed you know the GPS is not working and you need to fault trace. So the passage of time adds another piece of vital data that helps you decide that something is wrong (assuming the USA has not declared war and switched off the whole GPS system!)…whereas…
2. “No AIS” means two different things -
a. the AIS is fully functional, is receiving transmissions, but there are none to display, or
b. the AIS is NOT fully functional, is NOT receiving transmissions, and you need to due some fault tracing…straight away
This means you can set sail unaware that the AIS is faulty – but you would be totally aware if the GPS was faulty.
Please Raymarine, do something about AIS error detection – a suitable button could live nicely on the MARPA/AIS settings toolbar.
By Russ, on June 1st, 2008
I thought I would give a quick update on some of the more popular brands of AIS receiver and transponder, including some of the salient comparative features. Prices are approximate of course, when you look at your favourite online store I am sure you could better them – but it was interesting to note the price variations and also the way that features are not always a guide to price.
Note 1 : The unit has an Safety Related Message (SRM) button that allows the user to transmit a distress alert quickly and easily to all vessels and base stations within range. Often this button is programmed to engage “Silent Mode” when this “S” button is pressed. This means that it will only receive and not transmit – useful if you are worried about piracy!. The SRM feature is in addition to the international AIS specification and may not be monitored by all reception equipment. This feature does not replace use of normal VHF emergency procedures.
Note 2 : Comes with antenae
Note 3 : Comes with built in GPS – may be useful as a back up GPS to your normal one.
I applaud Raymarine for having brought this unit out earlier this year, it is good product marketing and market positioning (pun intended:-)
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