AIS transponder. Now you need it?

[NPMR]

Talking to a pal the other day, he was telling me about a visit to a Coastguard Office on some sort of 'official' visit - a PR day for the Coastguards, I think. Might have been Falmouth but at the most, Brixham - ho doesn't tend to travel very far.

One of the comments he made, was that he got the impression that the AIS 'screen' was the most used and that radar was little looked at - which is why the coastguard feel they can monitor stuff from a distance as they have "all the information".

I also spoke to a ferry captain (on the bridge of his ship) in October, and they use AIS to see what the other ships are doing as it's "easier" than the radar.

So, if we want to be seen, are we going to have to buy a transponder especially if we are going through any kind of shipping in our boats? Small planes do as a matter of course, and have done so for a long time.

I'm beginning to think we'll have to get one, even if it's not in the budget!

 

[HinewaisMan]

Out of interest, how much power do they use?

 

[Flossdog]

I've been thinking along those lines too. But, and it is a big but, yachties would have to be conscientious and NOT transmit when in, for example, the Solent on a bank holiday! Can you imagine what it would be like on the screen? You would not see the chart for all the AIS boxes. It is bad enough in Milford Haven sometimes.

 

[macd]

Out of interest, how much power do they use?

Dunno, but you can download user manuals for Digital Yacht's AIT1000 here, which should tell you:
http://www.digitalyacht.co.uk/product_info.php?products_id=11647

FIW, it uses a 3A fuse.

 

[PhillM]

Won't it be the case that if everyone uses a class B, then shipping will simply filter it out? I recall reading an article of a collision and the ship had filtered out "clutter" which included class B AIS transponders.

 

[Blue5]

Talking to a pal the other day, he was telling me about a visit to a Coastguard Office on some sort of 'official' visit - a PR day for the Coastguards, I think. Might have been Falmouth but at the most, Brixham - ho doesn't tend to travel very far.

One of the comments he made, was that he got the impression that the AIS 'screen' was the most used and that radar was little looked at - which is why the coastguard feel they can monitor stuff from a distance as they have "all the information".

I also spoke to a ferry captain (on the bridge of his ship) in October, and they use AIS to see what the other ships are doing as it's "easier" than the radar.

So, if we want to be seen, are we going to have to buy a transponder especially if we are going through any kind of shipping in our boats? Small planes do as a matter of course, and have done so for a long time.

I'm beginning to think we'll have to get one, even if it's not in the budget!

Brilliant bit of kit, helps reduce workload so no bad thing.

 

[Sandy]

The down side is SWMBO can see where you are:

http://www.marinetraffic.com/ais/

Nice sail down to the pub darling?

 

[[32511]]

I may be wrong, but I believe tha at presentt light aircraft are only required to have transponders in controlled airspace. Anyone confirm this? Interestingly, controlled airspace is being extended to windfarm locations.

 

[fireball]

Talking to a pal the other day, he was telling me about a visit to a Coastguard Office on some sort of 'official' visit - a PR day for the Coastguards, I think. Might have been Falmouth but at the most, Brixham - ho doesn't tend to travel very far.

One of the comments he made, was that he got the impression that the AIS 'screen' was the most used and that radar was little looked at - which is why the coastguard feel they can monitor stuff from a distance as they have "all the information".

I also spoke to a ferry captain (on the bridge of his ship) in October, and they use AIS to see what the other ships are doing as it's "easier" than the radar.

So, if we want to be seen, are we going to have to buy a transponder especially if we are going through any kind of shipping in our boats? Small planes do as a matter of course, and have done so for a long time.

I'm beginning to think we'll have to get one, even if it's not in the budget!

Do we really need the coastguard to sit there watching our every move?
I can understand the desire for big ships to be able to see us - so, if you were to venture into busy shipping channels on a frequent basis then I could understand the desire to get a transponder. However ...
the majority of ships still use Radar - and CG can still use Radar too ..

Best to go on the basis that the ship hasn't seen me and it's your duty to avoid it - stand on by all means - but not to the last minute...

 

[Ex-SolentBoy]

I've been thinking along those lines too. But, and it is a big but, yachties would have to be conscientious and NOT transmit when in, for example, the Solent on a bank holiday! Can you imagine what it would be like on the screen? You would not see the chart for all the AIS boxes. It is bad enough in Milford Haven sometimes.

I think there are several solutions to that.

We don't have to have data boxes. Someone can work out an icon that takes less space and can be interrogated for more details.

The screen will only be cluttered if you zoom out. Easy enough to provide a facility to switch on and off AIS targets for large scale viewing.

This is just something the plotter software designers need to sort out.

 

[Cardo]

We're currently refitting our 35 footer and will be adding a transponder. Haven't yet decided whether to get a radar.

 

[BrianH]

Won't it be the case that if everyone uses a class B, then shipping will simply filter it out? I recall reading an article of a collision and the ship had filtered out "clutter" which included class B AIS transponders.

The Furuno 2117 radar display that many commercial ships use to display the AIS targets has an AIS filter function menu - note function 4.

​

Hopefully, after clearing the Solent or other crowded leisure boat areas someone remembers to turn the filter 'OFF'

 

[Skysail]

I went to a conference on AIS B filtering recently. The attendance included ferry captains, pilots, leisure yachtsmen and harbour authorities.

The consensus was that AIS, while undoubtedly of value, is not the perfect answer. It is a victim of its own success and many people do not understand its limitations. Many ship installations are minimal. A Channel ferry captain said he never used it, preferring radar, and a pilot said the extra clutter overlaid on a radar screen (in the Solent) meant it was rarely used. Some ships filter out yachts in crowded situations. Add the increasing volume of leisure users, sea kayakers, fishing boats, dive boats (and divers!) and the situation will need a lot of clarification.

more here:

http://www.panbo.com/archives/2010/12/class_b_ais_filtering_the_word_from_dr_norris.html

 

[PhillM]

Makes me think that AIS could be more of use for looking out / keeping outo f the way of large ships, than relying on them to see us and keep clear. Perhaps a recieved is all that we need?

 

[westernman]

If you are less than 10m long or are making less than 1knot over ground, then it looks like you are pretty sure to be filtered out anyway......

Kind of defeats the point.

 

[pvb]

Any owner of a smallish boat who thinks buying an AIS transponder will ensure he's seen by shipping is impossibly optimistic.

 

[Goldie]

I may be wrong, but I believe that at present, light aircraft are only required to have transponders in controlled airspace. Anyone confirm this? Interestingly, controlled airspace is being extended to windfarm locations.

Not just light aircraft. There are categories of airspace where it's not even a requirement to have radio, let alone a transponder.

 

[fireball]

Perhaps a recieved is all that we need?

Given the current limitations - I believe a receiver is all we need. That and our own radar and a reasonable reflector - a seame may be more advisable if you're out playing in poor vis a lot ...

I think that perhaps dayglow orange sails might be a better answer ...

 

[wizard]

Makes me think that AIS could be more of use for looking out / keeping outo f the way of large ships, than relying on them to see us and keep clear. Perhaps a recieved is all that we need?

+1

 

[maxi77]

Talking to a pal the other day, he was telling me about a visit to a Coastguard Office on some sort of 'official' visit - a PR day for the Coastguards, I think. Might have been Falmouth but at the most, Brixham - ho doesn't tend to travel very far.

One of the comments he made, was that he got the impression that the AIS 'screen' was the most used and that radar was little looked at - which is why the coastguard feel they can monitor stuff from a distance as they have "all the information".

I also spoke to a ferry captain (on the bridge of his ship) in October, and they use AIS to see what the other ships are doing as it's "easier" than the radar.

So, if we want to be seen, are we going to have to buy a transponder especially if we are going through any kind of shipping in our boats? Small planes do as a matter of course, and have done so for a long time.

I'm beginning to think we'll have to get one, even if it's not in the budget!

I think you will find they will still have to have radar on display and being observed, and if they hit anything and do not have radar on and observed then the master will lose his ticket.

A long time ago I used to be involved in selling marine equipment, and we sold a radar which 'saw through' rain clutter using circular polarisation, but to be able to use it you had to have a normal polarised antenna back to back with your CP antenna. This way you had one sweep CP and saw most contacts in the rain, and then a normal sweep with rain clutter but perhaps some other contacts as well.