Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

RichardS

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Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

CLOSE ENCOUNTER WITH A FERRY

We were proceeding under engine power on a clear sunny day in the final stages of a voyage from the N coast of Mallorca to the S coast of Menorca when I spotted just forward of the beam a ferry leaving the coast as it cleared Ciutadella in Menorca travelling towards Mallorca. The vessel was also identified on Automatic Identfication System. Our yacht can receive but not transmit AIS. The weather was clear with excellent visibility on a smooth sea and I was able to watch the vessel from the time it left the coast and I tracked it visually and on AIS. The AIS indicated a CPA of about 0.2 miles. Our yacht was heading 104° true at 5.5 knots. The ferry was heading approximately 240° true on my port quarter. As it came closer the CPA decreased and the ship’s speed was around 20 knots (AIS) (maybe a little more). From my log I altered to starboard initially but was not clearing the ferry. We had crossed on 086T from an anchorage at Cala S. Vincent in Mallorca and our destination was Cala Santa Galdana in Menorca. As the ferry continued to close at speed it became obvious that the ferry would pass very close so I tried to contact it on VHF Channel 16 but received no reply. The ferry had plenty of room to pass either ahead or astern but seemed to head straight for the yacht. Due to its speed a close quarters situation rapidly developed and as the ferry was heading directly for the yacht I had few options as I can only make 6knots. An alteration to port would leave me close on its port side with a danger of it altering to starboard, an alteration to starboard would leave me in the ferries path. In the end I applied full throttle, cleared across the bow of the ferry and altered to port once passed. The ferry passed approximately 100m up my port side. Again I tried to contact via VHF Channel 16 but received no reply. The ferry made no course alterations despite being the give-way vessel. I also got the impression that a watch was not being kept on the ferry though I could not see onto the bridge to be sure.

The Maritime Advisory Board when reviewing this hazardous incident report, had sympathy with the reporter’s predicament in taking early and substantial action to avoid a small CPA to a fast moving vessel. They believe there could be similarities between this report and that addressing the sinking of the yacht Ouzo, see UK’s MAIB report 7/2007. As a result of the ferry company’s failure to respond to the report, and due to the severity of the report, the Flag State authority was informed of the failure to maintain a proper lookout and listening watch on VHF Channel 16.

The Maritime Advisory Board also brings to the attention of all leisure users, the following advice:

(a) Yachts often do not show up on a radar screen beyond about 5 miles, the radar wave passes through the GRP structure and reflects off the far side of the depression made in the water by the hull, then beyond that distance they do not show up on a radar screen due to a combination of too shallow an angle between the radar beam and the sea surface, interceptions from waves in front of the target and a reduction in signal strength according to the inverse square rule. When closer to the vessel, the yacht may be difficult to detect on the radar screen due to wave clutter.

(b) Radar reflectors have limited effect in improving the ability to enhance identification (RYA web site, MCA Marine Guidance Note M394 Carriage and Use of Radar Reflectors on Small Vessels paragraph 4.3).

(c) These issues will be detrimental to automated radar plotting aids and alerts and also to human observers, who may genuinely be having difficulty in detecting a yacht in the very large area of sea to the horizon.

(d) It would be prudent to incur an additional cost and install an AIS transponder additional to, or incorporating an AIS receiver. If there is concern over sufficient battery power, the yacht owner should turn on the engine and thereby power the batteries.

Interesting advice from the latest Chirp report. If you are thinking about an AIS receiver, the expert advice is to go for the transceiver.

Richard

PS Full report: https://s5.newzapp.co.uk/t/gtp_4.aspx?LID=OSw4MTU3NTM4ODUsMw==
 
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adwuk

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

If there was no lookout then a transmitter would have made little or no difference, and the advice would seem to indicate that an active radar reflector would be just as good a solution. Is it a case of have everything just in case?
 

wilkinsonsails

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

Transmitter would/could if active , provide an audible alarm,and record of track,for reference .
I have a transmitter and have noticed ships making course adjustment on a few occasions.
We have been called as well as a result of our AIS transmission,by the Coastguard asking for our assistance,and by a towing vessel asking for a wider berth.
I believe after having AIS transmitters onboard over the last 12 years that it's now a necessity ,particularly cruising in busy areas.
 

jbweston

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

The problem with AIS in busy waters is that there are just too many returns and alarms. So I've always imagined that other yachts/vessels do what I do, which is to turn my AIS receiver off when it gets busy so as to declutter the display and prevent task overload.

Out at sea is another matter. When nearly everyone's on autopilot the AIS course and speed data is predictable and AIS really helps me avoid close quarters situations.

But in confined waters, AIS is a distraction from keeping a visual lookout. More information is not necessarily better information. Often more is worse.
 

sailorman

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

it seems to me that a Sea Me would have been more effective, assuming the ferry had radar switched on
 

Seajet

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

A transmitter is spiffing, just don't rely on anyone who cares seeing it.

The passive display lets one choose one's own destiny...
 

temptress

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

Ignore Seajet's somewhat Luddite comment, and fit an active radar transponder and an AIS transceiver, in that order.

So here in Singapore it is now compulsory for ALL vessels with any form of motor (Sail or otherwise) with whatever national flag to have a compulsory SPA (Singapore Port Authority) approved Class B AIS AND PLOTTER when navigating in Singapore waters. (For Singapore veterans - this replaces the HARTS regulations)

A foreign flagged vessel without these will be permitted one trip into and out of Singapore waters only.
 

johnphilip

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

The problem with AIS in busy waters is that there are just too many returns and alarms. So I've always imagined that other yachts/vessels do what I do, which is to turn my AIS receiver off when it gets busy so as to declutter the display and prevent task overload.

Out at sea is another matter. When nearly everyone's on autopilot the AIS course and speed data is predictable and AIS really helps me avoid close quarters situations.

But in confined waters, AIS is a distraction from keeping a visual lookout. More information is not necessarily better information. Often more is worse.

+1
 

dom

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

The shipping industry seems to agree that an AIS transceiver is highly advisable for yachts navigating within areas of heavy traffic. In addition an X-Band radar transponder is also a good idea, and possibly S-Band too, which some of the bigger ships prefer in rough seas, lots of precipitation, etc.

FWIW a couple of ship's captains I have spoken to expressed amazement at the idea of AIS receiver only equipment. Their point is that, "you can already see us, but just want a bit more accuracy on the CPA, etc. We on the other hand can often barely see you on our radar (especially if its rough or raining) and could seriously use a few more clues!"
 

rotrax

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

I think, after trying to raise the ferry with no response that I would have called the Menorca Coastguard and appraised them of the situation.

They will invariably have a more powerfull transmitter than the usual leisure one fitted to a yacht and if they recieved no reply the OW/Captain would have been up $H1t creek without a paddle.

The ferries coming from and going to Ciutadella are noted for not changing course once they have hit the throttles.

Barstewards................................
 

sailorman

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

I think, after trying to raise the ferry with no response that I would have called the Menorca Coastguard and appraised them of the situation.

They will invariably have a more powerfull transmitter than the usual leisure one fitted to a yacht and if they recieved no reply the OW/Captain would have been up $H1t creek without a paddle.

The ferries coming from and going to Ciutadella are noted for not changing course once they have hit the throttles.

Barstewards................................
A rocket through the wheelhouse window might have got their attention :)
 

pvb

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

The shipping industry seems to agree that an AIS transceiver is highly advisable for yachts navigating within areas of heavy traffic. In addition an X-Band radar transponder is also a good idea, and possibly S-Band too, which some of the bigger ships prefer in rough seas, lots of precipitation, etc.

FWIW a couple of ship's captains I have spoken to expressed amazement at the idea of AIS receiver only equipment. Their point is that, "you can already see us, but just want a bit more accuracy on the CPA, etc. We on the other hand can often barely see you on our radar (especially if its rough or raining) and could seriously use a few more clues!"

Which reinforces the argument for fitting an active radar reflector in preference to an AIS transmitter. AIS equipment on ships isn't always integrated into their radar/plotter displays, and ships can (and do) filter out Class B AIS targets in busy areas. But all ships keep an eye on their radar. Unless you're convinced by the attraction of the "Look at me, I'm important, I've got an AIS transceiver", spending money on an active radar reflector is much better value in safety terms.
 

Spyro

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

The yacht skipper could just have slowed down and allowed the ferry to pass in front, Stand on vessel or not. I think That's what I would have done. Applying full throttle and crossing the bow of the ferry sounds like a recipe for disaster. He said he can only do 6 knots, he can also do 2.
 

pmagowan

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

I chose recieve only ais as it was integrated into my DSC radio. I mostly sail in the West coast of Scotland so it is not crowded. I have found it very useful but it can be a pain when entering a harbour as half the boats have transmit still on and thus you get a warning which takes the screen away from giving all the useful information. It is also hard to identify which boat you see on the horizon is which AIS target because there are invariably a number of small boats transmitting.

I think it is good technology but they need to write more clever algorithms to filter the results to stop clutter and confusion. It should be possible to turn off all stationary objects or ones that are moving away, thus only having important objects displayed. It would also be nice if people on yachts turned their ais off when they were in a harbour and not moving.
 

dom

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

Which reinforces the argument for fitting an active radar reflector in preference to an AIS transmitter. AIS equipment on ships isn't always integrated into their radar/plotter displays, and ships can (and do) filter out Class B AIS targets in busy areas. But all ships keep an eye on their radar. Unless you're convinced by the attraction of the "Look at me, I'm important, I've got an AIS transceiver", spending money on an active radar reflector is much better value in safety terms.

FWIW the captain's I spoke with (admittedly a somewhat limited sample confined to large container ships and RoRo ferries) all said that they only filter Class B in areas like the Solent, but never in places like the Channel, North Sea, etc, where they find AIS highly useful for spotting yachts, fishing boats, etc. Interestingly they view fishermen as the biggest pain in the neck by a country mile and apparently some of them dice with ships just coming out of the TSSs into the unrestricted water (i.e. the areas still loosely regarded as shipping lanes) precisely because these areas are less fished!

However, none of this reduces the validity of your argument and you are right to point out that radar and absolutely not AIS is regarded as the primary collision avoidance system.
 

RichardS

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

However, none of this reduces the validity of your argument and you are right to point out that radar and absolutely not AIS is regarded as the primary collision avoidance system.

The safety pendulum is swinging towards AIS though as it is virtually perfect for collision avoidance with anything that moves. As more fixed beacons are installed it will become dominant in more circumstances. The Singapore post above shows clearly where this is going.

I imagine that is the reason why the Advisory Board is saying that if you intend to fit an AIS receiver then whilst you're at it go for the transceiver.

When I drew up my list of what I wanted on my ideal boat 10 years ago, before I had actually bought one, I included active radar reflector and AIS receiver but not radar as in the Med fog is not an issue. By the time I was fitting out my boat 2 years ago active radar reflector had been crossed out and the AIS upgraded to a transceiver.

Richard
 

Tranona

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Re: Maritime Advisory Board says "Install an AIS transmitter and not just a receiver"

The problem with these sort of recommendations is that they are based on a "might have". why do they think that the ferry would have acted differently if the yacht had been transmitting an AIS signal? After all they did not pick the yacht up on radar nor visually when it was visible for a long time in (presumably) good visibility. There is only a requirement to keep a good lookout, not to specifically look for AIS signals from yachts, and some ships deliberately filter them out.

So the only real advice is that AIS gives an extra means of drawing the watchkeepers attention to a yacht but it still relies on the watchkeeper first seeing the signal and second taking action if necessary to avoid a collision.

This incident did not "prove" that AIS is effective.
 
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