AIS

maby said:
I'm guessing that he may have missed the "active" bit - passive reflectors are close to worthless unless they are expensive and large.
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Perhaps, but I am looking forward to the day I remove the inactive reflector and add an active one.
 
I had an RNLI On Board check recently and the following weekend had the opportunity to talk with a RNLI crew trainer. On the subject of AIS and Radar I gathered the following info for vessels greater that 3 miles offshore:

1) A radar reflector essential to have one on board preferably fixed in position where it works effectively.
2) Yachts are more difficult to find on Radar without a decent Radar reflection. Just a fibreglass yacht, a mast and even wet sails are not very effective. Hence an effective reflector or a Radar Target Enhancer is essential. if an Active RTE rigged then have a hoist type reflector as well in case the power fails.
3) On an RNLI lifeboat there are only very rare occasions when no one is sat in Radar seat.
4) RNLI lifeboats use AIS as well. Example of a use for AIS and Radar they gave me was interesting:
Lifeboat is called out from Poole to search the areas of Poole Bay and Christchurch Bay for a missing yacht. There are approx 40 yachts found on AIS/Radar and mk1 eyeball. 30 of the yachts have AIS so they immediately cross those off the investigation list. That leaves 10 vessels they have to get close enough to to indentify if it is the missing yacht they are looking for. So this results is many miles of rescue speed miles to identify 10 yachts. Meanwhile another lifeboat is doing the same searching the Eastern end of the Solent approaches. If all/most of the vessels had AIS then it would have used up a lot less time and resources to establish the missing yacht is not in the area. The moral here is AIS on one yacht unknowingly helped the rescue services to rescue another yacht/sailor, not your own.

Anyway, aside from the senario given above, I have installed on my yacht an RTE (Dual Band) and a back up hoist reflector. Main reason for this is because small boat Radar reflectors are well reported as being somewhere between unreliable to useless. I feel very comforted that my yacht radar reflection is reliably ( from memory) somewhere between 20 to 80 m squ.
 
BelleSerene said:
Yes, I do appreciate that. Still, the colregs being the collision - er - regulations, when anything happens and you weren’t following them, tell that to the judge! ‘Cautious’ quoted in isolation sounds fine. But in practice, if you weren’t obeying the regulations, you’re the guilty party!
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The bottom line of the colregs is that it is the responsibility of all to navigate in such a manner as to avoid collisions:
"Rule 2
Responsibility
(a). Nothing in these Rules shall exonerate any vessel, or the owner, master or crew thereof, from the consequences of
any neglect to comply with these Rules or of the neglect of any precaution which may be required by the ordinary
practice of seamen, or by the special circumstances of the case.
(b). In construing and complying with these Rules due regard shall be had to all dangers of navigation and collision and
to any special circumstances, including the limitations of the vessels involved, which may make a departure from these
Rules necessary to avoid immediate danger. "

and;

"Rule 17
Action by stand-on vessel
(a).
(i). Where one of two vessels is to keep out of the way the other shall keep her course and speed.
(ii). The latter vessel may however take action to avoid collision by her manoeuvre alone, as soon as it becomes
apparent to her that the vessel required to keep out of the way is not taking appropriate action in compliance with these
Rules.
(b). When, from any cause, the vessel required to keep her course and speed finds herself so close that collision
cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid
collision.
(c). A power-driven vessel which takes action in a crossing situation in accordance with subparagraph (a)(ii) of this Rule
to avoid collision with another power-driven vessel shall, if the circumstances of the case admit, not alter course to port
for a vessel on her own port side.
(d). This Rule does not relieve the give-way vessel of her obligation to keep out of the way."
 
PaulRainbow said:
All fair points, but i can't see where transmitting AIS changes any of them.
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Rule 5......." by all available means"

Rule 5
Look-out
. Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means
appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk
of collision.
I believe the thread drift had moved in the direction of "not transmitting AIS", rather than "Transmitting..."
 
Spirit (of Glenans) said:
Rule 5......." by all available means"

Rule 5
Look-out
. Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means
appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk
of collision.
I believe the thread drift had moved in the direction of "not transmitting AIS", rather than "Transmitting..."
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Transmitting AIS cannot in any way be construed as keeping a look-out.
 
Spirit (of Glenans) said:
The bottom line of the colregs is that it is the responsibility of all to navigate in such a manner as to avoid collisions...

"Rule 17
Action by stand-on vessel
(a).
(i). Where one of two vessels is to keep out of the way the other shall keep her course and speed
Click to expand...

That’s right, thanks. The comment you quoted was in response to this:

The trouble with taking what you called ‘a more cautious approach than that might be interpreted from the colregs when navigating in the vicinity of ships’ is that you break a critical rule like the one you quote above, and that creates confusion for the other vessel, however large it is, which increases the hazard to all. Once we get to the stage when the stand-on vessel clearly isn’t keeping out of the way, the rules already state that we’re all responsible to take avoiding action. But that doesn’t relieve us as stand-on vessel from the clear responsibility to stand on.

My quote, which you are reacting to, was in response to MartynG’s claim that we should throw the rules to the wind and just scarper when a large commercial vessel was around - a recipe for chaos on the seas:

MartynG said:
The leisure craft skipper being in charge of the more maneuverable vessel should always take action to avoid a collision. I don't care what the colregs say - keeping out of the way of ships is the responsibility of leisure craft skippers.
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BelleSerene said:
That’s right, thanks. The comment you quoted was in response to this:

The trouble with taking what you called ‘a more cautious approach than that might be interpreted from the colregs when navigating in the vicinity of ships’ is that you break a critical rule like the one you quote above, and that creates confusion for the other vessel, however large it is, which increases the hazard to all. Once we get to the stage when the stand-on vessel clearly isn’t keeping out of the way, the rules already state that we’re all responsible to take avoiding action. But that doesn’t relieve us as stand-on vessel from the clear responsibility to stand on.

My quote, which you are reacting to, was in response to MartynG’s claim that we should throw the rules to the wind and just scarper when a large commercial vessel was around - a recipe for chaos on the seas:
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We've had this debate several times.

If action is taken early enough, a risk of collision will not exist and you are free to manouver however you wish, there won't be a stand on vessel or a give way vessel. With AIS we can see from several miles away exactly what that super tanker on the horizon is doing and if we can make a course change well before Colregs kick in. We then don't get into a situation where we might become the stand on vessel and are then wondering if the super tanker really will change course for our little leasure boat, or not.

Done early enough, no Colregs are thrown to the wind and i'd call that good seamanship.
 
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PaulRainbow said:
We've had this debate several times.

If action is taken early enough, a risk of collision will not exist and you are free to manouver however you wish, there won't be a stand on vessel or a give way vessel. With AIS we can see from several miles away exactly what that super tanker on the horizon is doing and if we can make a course change well before Colregs kick in. We then don't get into a situation where we might become the stand on vessel and are then wondering if the super tanker really will change course for out little leasure boat, or not.

Done early enough, no Colregs are thrown to the wind and i'd call that good seamanship.
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Indeed so.

I can see vessels on my AIS which are not even over the horizon so cannot be seen, period. I can also see on the screen that we are on a collision course.

If I did not have AIS I would not even know that there was a vessel over the horizon and, as I'm sailing along in blissful ignorance of what is not going to become visually clear for another 30 minutes, I could, serendipitously, alter course away from the hidden vessel .... so I might just do that and the Col Regs Police would be none the wiser. ;)

Richard
 
BelleSerene said:
My quote, which you are reacting to, was in response to MartynG’s claim that we should throw the rules to the wind and just scarper when a large commercial vessel was around - a recipe for chaos on the seas:
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Agree 110%. Everything you ever need is covered by the IRPCS. Which doesn't forbid early course changes if you want.
 
In reply to MartynG and BelleSerene is that I found, while crewing late last year on a passage from Concarneau to Bayona, Spain, was that with the use of an AIS transceiver it was possible to observe on screen the course, bearing and CPAs of large vessels approaching ahead or astern, initially around 20 miles away. Standing on and monitoring the course of the nearest targets I could watch what was happening with their CPAs and whether or not they had made minor adjustments to their courses in order to avoid me . This then informed my decisions regarding my own course. Hence broadcasting AIS can be part of keeping watch.
There is also the point that,technically, the watchkeeper on the merchant vessel should also be monitoring AIS, both Class A and B, in the interest of keeping a good lookout by every available means.
 
Spirit (of Glenans) said:
with the use of an AIS transceiver ... I could watch what was happening with their CPAs... This then informed my decisions regarding my own course. Hence broadcasting AIS can be part of keeping watch.
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Well scrubbing the decks, filling in the log and trimming the sails are also all part of keeping watch. But let’s not confuse any of them with keeping a good lookout. None of them does that - including broadcasting AIS.

Receiving AIS can be part of keeping a lookout, but however necessary you consider it is, it’s not sufficient.

As for transmitting AIS, yes, that’s how it works and that’s why it’s useful.
 
I have had an AIS transceiver on board for two years now and in that time it has been actively used 3 times that I am aware of. On one occasion I was approaching Sheerness harbour. I was monitoring the VTS channel listening to a Car transporter about to leave. They were concerned about the amount of leisure traffic in the harbour. They were assured by VTS the bulk of leisure traffic was clear, but one Yacht "Jeddo" was approaching the harbour from the East. They had seen me on AIS. I was then able to inform them I was aware of the Car transporter and would keep clear. Without AIS it would have just been another Yacht.
On another occasion I had crossed the channel with two other boats, when one discovered, about 2 miles off Dover he had a fouled prop. With the continuous stream of ferries panic set in and was suddenly unable to continue to sail as we had done all the way across the channel. The inexperienced crew ended up requesting assistance from the Coastguard. Only a partial position was given. I was able to give the CG the correct position and inform them I was transmitting AIS and staying close. Whilst waiting for the Lifeboat we managed to talk them into getting the boat sailing again and clear of the ferry route in and out of Dover. The Lifeboat used my AIS to come directly to us without a search.
Earlier this year, we were sailing from Oostende to Gravelines and strayed into a poorly marked on the charts, live firing range. After a little confusion with the the Flemish pronounciation of the letter "J" as a "Y" the range was able to contact us over VHF rather than sending out a patrol launch.
 
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