AIS

I went with a Digital Yacht AIT2000 transponder, at the time I was drawn to it for its multiple connectivity options (NMEA 0183, NMEA 2000 and USB).

I simultaneously use the NMEA 0183 HS output to the fixed Garmin chartplotter and also the USB connection into my laptop running OpenCPN which is far better at showing the AIS contacts. Whilst we have no other NMEA 2000 devices onboard at the moment knowing that it should be simple to connect should I choose to upgrade was also a factor.

It's been installed for coming up to a year now and I've been happy with its performance to date and would recommend it.

Past experience of Digital Yacht's website is that its often unavailable over the weekend but I'd expect it to be working again tomorrow (Monday). www.digitalyacht.co.uk

Digital Yacht Website back online as per above. I have digital yacht AIS - great piece of kit
 
AIS on a very small screen is problematic, but on a 5" plotter screen it's OK. Can I ask why transponder? I don't want to repeat all the reasons why it's of little value but if you have a spare £500 extra, why not spend it on either a seeme and actually be seen on ship's screens, or on a larger and better functioned plotter for better display of recieved signals.

I would be grateful if you would expand on the reasons why you consider a seeme to be a better bet than an AIS transponder. Seeme will give a better radar echo, but it will depend on the ship's radar set up and the operator as to how well it is interpreted and the action taken (see Bill Anderson's Question of Seamanship article in May 2013 Yachting Monthly). AIS info can also be displayed on modern ship's radar displays and chartplotters and, I would think be less likely to misinterpretation of heading and speed etc. To my mind, I think I would install an AIS transponder as initial choice. I look forward to your comments!
 
I would be grateful if you would expand on the reasons why you consider a seeme to be a better bet than an AIS transponder.

Mostly just that ship's officers live and die by their radar, and have done for their whole careers, whereas AIS is still relatively new. An increasing number of ships will display both on the same screen, but there will still be plenty (I'd be interested to hear the proportion, from anyone who knows) with older radars that don't display AIS, and possibly even with just the minimum mandatory AIS fit which is a small text display showing the coordinates of three targets. I'm aware that at some point this argument will become out of date, and I don't want to hang onto it past its sell-by date, but currently of my sample of two ships' bridges I've been on, 100% have had only the minimum AIS fit. The watchkeepers did, however, spend nearly all their time sitting in front of the radar. An AIS transmitter will make you visible to the proportion of ships with a modern bridge fit; a radar target enhancer will make you visible to practically all commercial vessels (even small tugs and launches carry radar).

There's a tradeoff to be made, and I wouldn't suggest that anyone fitting AIS transmit before RTE is being foolish - but you asked for the reasons and those are them.

Pete
 
The best presentation of AIS data is on OpenCPN with the CM93 chart detail turned right down. CPA is very clearly displayed and the alarms are very flexible.
I appreciate that this needs a netbook (or higher) to run and they consume amps, but it's better to improve your battery system than to buy an expensive (dedicated) display IMHO.

I agree with your assessment here, I use an identical configuration (netbook running OCPN) below on the chart table as backup to my Garmin plotter in the pilot-house - except that, for me, the alarms are not flexible enough. Why? I cannot suppress the constant alarms from the burgeoning Class B transmissions.

Last year I had to turn off the CPA alarm entirely, putting me in very real danger from the cowboy drivers of fast ferries that ply my cruising waters in the northern Adriatic and who can really kill me - I have had two near misses; one I had to call on channel 16 when only 1.1 NM away and headed straight at me with a closing speed of 35 knots, before he swerved away. At least I had the ship's name from the AIS report to call with.

The masses of yachts that have suddenly embraced AIS transponders and keep them permanently transmitting makes it a tiresome business to keep going below to cancel the next yacht that tacks onto my path somewhere.

I did propose a feature request in the relevant OpenCPN thread on the Cruisers & Sailing Forum but it seemed to go down like a lead balloon.
 
Last year I had to turn off the CPA alarm entirely, putting me in very real danger from the cowboy drivers of fast ferries that ply my cruising waters in the northern Adriatic

Watchmate can use the target's speed as a criterion in the CPA alarm configuration, so you could be alerted to the fast ferries while ignoring the slower yachts.

Pete
 
I recently fitted a SH GX2150 integrated with my Raymarine C80 chartplotter. Very happy with the AIS display through my C80 and I can operate the VHF and all its features from the cockpit using the SH command mike.
 
Watchmate can use the target's speed as a criterion in the CPA alarm configuration, so you could be alerted to the fast ferries while ignoring the slower yachts.
Thanks Pete, that seems to be a solution. A pity that OCPN cannot do the same. I can appreciate that to disable alarms on Class appears a drastic solution, the Watchmate solution would solve that. Perhaps I'll try again with that proposal to the developers.
 
There's a tradeoff to be made, and I wouldn't suggest that anyone fitting AIS transmit before RTE is being foolish - but you asked for the reasons and those are them.

Pete

Thank you Pete. Good thinking. I Guess you could also add that small fishing vessels will at least have a radar etc. I agree it is a close call and ideally one would have both. I have just gone through this thought process and came out in favour of AIS Tx as more info given and I am generally more scared of big ships traveling at speed with limited maneuverability.
 
Fitted a vesper 850 watchmate last year very good bit of kit though not exactly cheap. I like having a separate display for it and have it mounted next to the chart plotter.

John
 
I just looked at the price of that Vespa Watchmate transponder, and it's over £700!

I'm sure it's very good, but there's got to be a better way of doing all this marine electronics malarkey than lots of dedicated devices, all with their own screens and all prone to obsolescence.

A ruggedised, waterproof Android tablet with a 12v socket could provide the brains and display for a more modular system. Functionally such as AIS could then be added via series of headless hardware modules. Extra tablets could be mounted in the cockpit or anywhere else they are needed, and the whole lot could be networked together. All you would then need is an app like iNavX to bring it all together on one screen, preferably with a better user experience. Other dedicated apps could be used (and switched between) if more bespoke functionality is required.

A modular system based on an open OS would mean that bits of hardware could be upgraded over time and at less cost, while software can be continually updated via the existing app store type infrastructure.

What does the panel think? As someone who works with technology on a daily basis I have to say that marine electronics often appears to be in the dark ages.
 
What does the panel think?

I think all that could be done. But unless you're proposing some kind of open-source self-help model, I suspect that by the time you've paid for development and manufacture, when you come to divide the cost among the couple of thousand units you'll probably sell, the price may not be much different from the existing solutions.

Small market size is the main reason that leisure marine kit seems to lag behind general consumer electronics.

Pete
 
I think all that could be done. But unless you're proposing some kind of open-source self-help model, I suspect that by the time you've paid for development and manufacture, when you come to divide the cost among the couple of thousand units you'll probably sell, the price may not be much different from the existing solutions.

Small market size is the main reason that leisure marine kit seems to lag behind general consumer electronics.

Pete

There's already bits of hardware and software around for a modular system but what's really lacking is an appropriate rugged tablet.

I use the DMK Box (GPS and NMEA wireless mux) and an iPad running iNavX. I have the iPad in a waterproof case, but what I'd really like is a tablet built for marine use, with a daylight viewable screen and designed to be permanently plugged into a 12V supply.

I think if such a thing existed at the right price then more software and hardware innovation would follow.
 
+1 for Watchmate
We have their display only version connected to a Digital Yacht Transponder.
Excellent.
The DY also feeds a Furuno plotter.
Watchmate 0.1 amp. Plotter 5 amps.
Watchmate stays on, DY transmits when appropriate.
Plotter is only used for coastal work. and often disable the plotter alarms as the Watchmate alarms are MUCH more configurable.
 
I would be grateful if you would expand on the reasons why you consider a seeme to be a better bet than an AIS transponder. Seeme will give a better radar echo, but it will depend on the ship's radar set up and the operator as to how well it is interpreted and the action taken (see Bill Anderson's Question of Seamanship article in May 2013 Yachting Monthly). AIS info can also be displayed on modern ship's radar displays and chartplotters and, I would think be less likely to misinterpretation of heading and speed etc. To my mind, I think I would install an AIS transponder as initial choice. I look forward to your comments!

Not much to add to prv's excellent summary. About 90% of commercial shipping does not display AIS on a combined plotter/radar screen, a few have separate AIS screens but the vast, vast majority have a small screen with three lines of text sowing the lat and long of the three nearest AIS targets. All newly registered UK ships must have a bridge AIS screen fitted, so in 30 years the situation will be different for UK flagged ships. But in the meantime all commercial vessels do what they've done pretty skilfully for the last 50 years and that's use radar. Then add to that the ability of commercial vessels to turn off class B signals when in areas with crowded signals and you begin to see the pointless nature of class B transponders. Have a look at an AIS enabled plotter screen in the Solent this summer, it will be covered in AIS targets, so in order to see the details of the chart, many yachts will be turning off AIS reception. Class A AIS is a brilliant system for giving us all vital information on ships, class B transponders are an almost complete irrelevance that degrades safety rather than enhances it
 
Not much to add to prv's excellent summary. About 90% of commercial shipping does not display AIS on a combined plotter/radar screen, a few have separate AIS screens but the vast, vast majority have a small screen with three lines of text sowing the lat and long of the three nearest AIS targets. All newly registered UK ships must have a bridge AIS screen fitted, so in 30 years the situation will be different for UK flagged ships. But in the meantime all commercial vessels do what they've done pretty skilfully for the last 50 years and that's use radar. Then add to that the ability of commercial vessels to turn off class B signals when in areas with crowded signals and you begin to see the pointless nature of class B transponders. Have a look at an AIS enabled plotter screen in the Solent this summer, it will be covered in AIS targets, so in order to see the details of the chart, many yachts will be turning off AIS reception. Class A AIS is a brilliant system for giving us all vital information on ships, class B transponders are an almost complete irrelevance that degrades safety rather than enhances it

Even in the relatively less crowded East Coast, I quickly learnt to disable the AIS alarms at the plotter and instrument heads when they were conistently being set off by class B units moored in the various Orwell marinas.

The alarms go back on once out of the river - a minor annoyance but I do feel it degrades to usefulness of the AIS system.
 
Even in the relatively less crowded East Coast, I quickly learnt to disable the AIS alarms at the plotter and instrument heads when they were conistently being set off by class B units moored in the various Orwell marinas.
The alarms go back on once out of the river - a minor annoyance but I do feel it degrades to usefulness of the AIS system.
It may be a minor annoyance to you but it is a major problem for me where I sail because the alarm has to be permanently disabled - see my post #25. I have managed with an AIS receiver only for ten years now and have no intention to add a transponder, preferring to be responsible for my own avoidance actions.

Far better to invest in an active radar transponder than an AIS one - Class B clutter is an abomination.
 
Even in the relatively less crowded East Coast, I quickly learnt to disable the AIS alarms at the plotter and instrument heads when they were conistently being set off by class B units moored in the various Orwell marinas.

The alarms go back on once out of the river - a minor annoyance but I do feel it degrades to usefulness of the AIS system.

This is just another example of why decent filtering is important. Dare I say Watchmate again? They can ignore targets that are not moving.

No, I'm not on commission, but it's this kind of issue due to lack of thought and experience on the part of the designer that drove my research to find a solution other than a plotter with AIS tacked on as an afterthought.

Pete
 
. Then add to that the ability of commercial vessels to turn off class B signals when in areas with crowded signals and you begin to see the pointless nature of class B transponders.

I am a little surprised that it is possible to disable the reception of Class B versus Class A, since my understanding is that they broadcast on the same frequencies but with Class B at a lower priority and power. Quoting Wikipedia - both Class A and Class B equipment receive all types of AIS messages.

I fully agree with the nonsense of Class B transmission from small craft in crowded waters which totally clutters the screen. There should be some advice for it use only where necessary. However, radar also suffers from clutter in crowded waters.
 
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