AIS for coastal sailing?

[Peter K]

What are people's experiences with AIS receivers / transponders?      Are they useful for Coastal/Inshore sailing or is there too much information to see on a small screen, especially with more yachts having transponders?   

I don't have AIS on my BC 26 , but have a 7" chart plotter (Garmin 722XS).  ( And MK 1 eyeballs :-)).  Chatting to other owners, sounds like I am in a minority.

Browsing old forum posts, AIS is also mentioned for BR/Bre's in  "Mininal safety gear ... " http://www.swallowyachtsassociation.org/smf/index.php/topic,1400.0.html

I am thinking of spending some time in the West / Solent, hence the question: I don't feel the need for AIS  on the East Coast.

Many thanks,

Peter

[Rob Johnstone]

Hi Peter,
I think that an AIS receiver that  "talks to" your charter plotter and display contacts (and assess their danger) is essential when sailing in congested waters, particularly where fast ferries and gas / oil / wind turbine support vessels operate. Several times the receiver/plotter combination warned me of possible collision situations from such vessels, particularly in misty conditions. Vagabond only had an AIS receiver, as does Riff Raff - if I was sure I had enough charging capability I would have installed either an echo max type radar transponder or an AIS transmitter.
So, I think you have to have an AIS receiver as a minimum in the Solent.

Peter Taylor will probably have something to say about the matter - I know he has AIS of both sorts and an echomax!

[Peter K]

Thanks Rob.

I have 2 x 30W solar panels (& extra battery): what do you have on Vagabond?

Peter

[Andy Dingle]

In my experience I think AIS is an important tool if you are sailing in busy estuary/harbour area's - even if it is not linked to a chart plotter it can be set to sound an alarm if anything comes too close, or is on a potential collision course.
I use the Standard Horizon GX2200E VHF which gives an AIS output (easily linked to a chartplotter/laptop etc) without having to use a separate receiver and split/dual vhf aerials, it also has a gps output and it displays AIS 'targets' on it's built in screen. In my opinion this is the best fixed VHF available out there.

If I was equipping again I would definitely go for an AIS transponder too after some of my 'adventures' again this year...! It's somewhat re-assuring to know the local VTS can see where you are ...

For power I have twin 20w solar panels and two AGM batteries - backed up with a Ctek 'smart' charger as I have shore power too.

Andy and Equinox
BC23

[Rob Johnstone]

Riff Raff has two 48 ah batts swtched independently to power the boat. 2 x 25 ? Watt solar panels have a charge controller that splits the charge between each battery. I've just sailed (well, some of the time) from Chichester through the Solent to Yarmouth. The display on the chart plotter was full of AIS transmissions. The surroundings of Cowes gave alarm inductions every minute or zo at one point and I had to turn off the "audible" function. Riff Raff seemed to be one of few yachts without a transmitter.
So far we're three days out without  needing shore power. That 's using wind instruments, dsc/ais radio and Garmin chart plotter. Both batts are at 90 % charge despite an overcast day today.
( Rifff Raff replaced Vagabond this year )
Rob

[Andy Dingle]

Re batteries/power supplies.. I have pretty much the same as you Rob and much the same instrumentation. I only charged the batteries from solar power for three years. Last year both died on me - Irreparably!
Not sure if this is good going or not, but some bloke in the club who reckons he knows stuff, said I needed to charge the new one's properly every so often - hence the smart charger and they should last longer.. who knows?

[Rob Johnstone]

Hmm, Andy, I think you might be right about needing a "real" charge from time to time. At the end of my "4 day cruise of the Solent", including 2 over cast days, one battery was down to 80% charge, according to the charge monitor device. As I had "free" electric on the pontoon in the last marina of the trip I connected the wizzo battery charger to that battery. It took 4 hours to get that battery to a "fully charged" state and was charging at 6 amps for the first 30 minutes!

Back to the AIS point about this thread, below is a photo taken from the screen of the chart plotter some time last Saturday, somewhere in the Solent off Portsmouth. All the boats showing on the screen were "pleasure" and no, we didn't meet - but did pass close by!

[Peter K]

Many thanks for the AIS advice, Rob and Andy.

Good to know about the batteries - I have not been charging from shore power.

Peter

[Peter Taylor]

As Rob has said I have an active AIS system ("transponder") and also an Echomax X-band radio transponder. I have them because each time I leave the jetty in the River Itchen I pass through part of the Port of Southampton and then proceed to sail on Southampton Water and the Solent. Rob''s AIS plot looks quite quiet to me... At this time of the year at midday at the weekend there are typically 300 to 400 pleasure craft in clear view of the Coastwatch station at Calshot Tower!

Apart from the initial cost, the disadvantage of an active AIS system is the power consumption - it needs its own GPS receiver and it is transmitting - the Digital Yacht AIT2000 I have uses typically 0.3A at 12V. "Receiving only" has much less power cost. As Andy says, for that the best way is to have a radio with a built in receiver.

Advantages of an AIS receiver:  I find having AIS displayed on the chart plotter is most useful for knowing where the  fast "Redjet" ferries are when I want to cross the shipping channel. Also I can check where a large "clear channel" ship is if I've heard from VTS that one is in the area. Redjets travel at over 30kts, a clear channel ship might be doing near 20 kts.  It also alerts me to other yachts which are behind the sails and on a collision course - yes, you have to keep looking yourself, lots of boats don't have AIS, but it's another source of information. Well worth it in my view.

Is it worth having an AIS transmitter? I don't know! I see it as a belt and braces approach. In bad visibility it will allow the Redjets and other ships to see where I am, but there are lots of fast pleasure craft out there who may not be looking at AIS. In the Solent it's probably a good idea, elsewhere perhaps less necessary.

A note on radar: be aware that the small tubular radar reflectors are more or less useless. Indeed, worse than that, they give a false sense of security (there is a Qinetiq report CR0704527 ). An efficient radar reflector is bigger than most of us would want up the mast of a Swallow Yacht. I have an Echomax X-band transponder because ships in near shore waters are more likely to be watching x-band - dual band (S+X) is better if you can afford it and if you are likely to be going offshore e.g. across the channel. The main disadvantage of the transponder is you can see LEDs flashing on the electronics box but you don't actually know that it is working! And, again, it is another sink for electrical power. But it is better than having a useless small radar reflector!

Peter

[Sea Simon]

Perhaps not quite the same thing, but....this might be helpful to some?

If you don't  want to splash out on a pukka AIS system, or perhaps like me you have no power supply onboard, there are several AIS "apps" available (I use only Android devices).
There even used to be one (i forget the name) that claimed to be a transmitter, but as i was never able to test it properly, I deleted it.

"AIS live" used to be excellent, good enough for professional use, appears to have become subscription only and i no longer have access to a key.
Atm I am using  "vessel finder free" and that serves my needs in terms of ship spotting, from an "anorak's" perspective. I can't vouch for it as a nav aid, but refresh rates are adequate for information purposes, at least in my usual West Country sailing areas.

I used to live/sail on the Solent, and you are right to be very wary of the fast ferries (at least they run to some sort of timetable) and military hovercraft etc. Never mind the assorted prats in very large RHIBs or even full-on racing power boats.
Can't say I miss the Solent, Cowes etc.....too much like the M25 with the added possibility of drowning

[Peter Taylor]

If you don't  want to splash out on a pukka AIS system, or perhaps like me you have no power supply onboard, there are several AIS "apps" available (I use only Android devices).

Good point. It would be interesting to know which apps if any people use/find good. "Marine Traffic" is popular and available either over the web or as an app but if you want to apply filters to make it more useful as a real time device (e.g. only show recently received positions) you have to subscribe. Otherwise you get positions up to 1 day old. Even so the free version will allow you to detect fast ferries before crossing the shipping lane. Be aware that it will eat up your phone/tablet's data quota if left on all the time.

BTW re. fast ferries, note that the Redjets do not always stay in the shipping channel! If there is a "clear channel" vessel around I've even seen then outside the "small greens" in Southampton Water.

Peter