MAIB Report

[Bergman]

"I would agree in large measure with much of your comment"

Thank you

I too believe that our views are fairly close.

I agree that we all have a responsibility for our own safety, but not to the extent of allowing others to be complacent.

IMO standards dictate a minimum level of performance, there is no regulatory reason that I am aware of that prevents a company exceeding the minimum standards.

PeterB's description provides a very good example of how a small item can be found among clutter, and Pye end buoy, if my memory serves right, is much smaller than a 25 ft yacht. What Peter did manually could have been done electronically I am certain, given the motivation to create the capability to do it.

I agree about providing a decent RCS, which hopefully will be facilitated by the Qinetic (I still think DERA) report. I do not entirely agree that this "puts the ball in our court" Clearly there are issues surrounding the effectiveness of radar reflectors and the sooner there is better information available the happier I for one will be. I have little or no confidence in the presently available stuff.

If the answer is that the only way to give a decent reflection is to move to some sort of active device then a clear statement from Qinetic would help. Presumably such a statement would create a demand which would encourage supply which would bring down the price (yeah OK I'll dream on) however this in itself could create a range of new issues.

But

So long as Colregs puts an onus on a vessel to take positive action to avoid another vessel they cannot abdicate the responsibility for being able to detect that vessel's presence. So the ball can never be fully in our court. Zero complacency must apply to everyone who goes to sea, and everyone who is involved in the creation and policing of international regulations as well.

 

[Skyva_2]

Interesting and timely discussion here:

RSYC Radar

It also seems very possible to me that Pye End buoy has a larger RCS than a 25ft GRP yacht, if this is the buoy in question:

http://www.cam.net.uk/home/sail/camsailnews/newsletter50.pdf

 

[Bergman]

Frankly I lost this document on the 2nd paragraph:

"IMO regulations REQUIRE you to fit best radar reflector you can. MCA guidance is that almost every vessel can and must carry a reflector."

How can IMO or any other regulation require you to fit the best reflector.

They do not know which one is the best.

How do they define best - a sheet copper mainsail?

Is whats best for a sailing boat best for a moror cruiser?

What do they mean by the best you can - what are the limiting factors. Do they mean one you can afford, or the biggest you can lift?

They do not define what is best.

If IMO "REQUIRE" how is it that MAIB can only recommend.

And why does it recommend "almost" every vessel - what vessels are recommended not to use one - and why

Really publishing stuff like this does not help anyone.

Sadly the "science" that follows this passage loses any credibility it may have by being preceded by this stuff.

It really would be better to wait and see what Qinetic can come up with

As for Pye End buoy - yes I guess its possible it does have a greater RCS than a 25 ft yacht, but then again, its possible it doesn't. I don't know which. Perhaps it depends upon the yacht. But I can't help thinking that sticking a metal tube 30 ft up in the air, surrounded by steel wires and with a few aluminium bits screwed to it would help a bit.

But then I'm no expert.

 

[Sinbad2222]

The RSYC article is IMHO excellent. However it begs the question by recommending,rather lamely,that we should fit the "best " reflector. The question is what is best and would that be better than the hole in the water made by our boat or the engine block. The US study I referred to above in fact found that the corner reflector,although cheap and cheerful,was in fact better than the Firdell Blipper, the Cyclops and the Mobri. These latter devices widely seen on the continent are rather amusingly said to be only useful on a stealth bomber.
I'm afraid that no amount of reseach at Funtigdon will overcome the basic physics that for practical purposes the signal to noise ratio is inadequate in other than calm waters.

 

[Skyva_2]

I also thought the RSYC article was good. Apparently Prof Mullarkey had a hand in the the new Raymarine H6.

As for passive reflectors, based on what I read I went for the Echomax. As the article says, the authors will not make that conclusion. These days it would just lay you open to compensation claims. They do recommend looking at the published polar diagrams, and draw your own conclusions.

Even a vertical mast is a pretty useless reflector; heeled it is even worse. Useful for Xmas decorations, rather like some reflectors. I agree we are fighting the laws of physics here.

 

[johnalison]

As I understand it, the main advantage of an active reflector is that it returns a greater proportion of echoes and is therefore much more likely to set off a ship's automatic collision avoidance system, the effect being more marked in poor seeing conditions.

In my experience, most yachts can be seen in good conditions up to about 2 1/2miles even without a reflector on my 2 Kw radar. My plan is to give myself the best chance of being seen even if the odd ship is not properly conducted and so I have a SeaMe fitted. We appear to have very few close encounters (touch wood) which I naively attribute to my radar visibility.

 

[Slow_boat]

Is the old aluminium dodecohedron in the 'raincatcher' position still considered the most effective?

Is there a radar reflector that will set off an alarm if it detects a radar 'looking' at it?

 

[Skyva_2]

The octahedron is good value for money but not nearly as reflective as the Echomax.

The Sea-me will raise an alarm if it detects a radar signal; it is an active reflector, having its own power supply, it does not reflect echoes but sends its own signal when it detects another.

 

[Slow_boat]

Thanks.

I've just looked up the prices;

Echomax midi - £124.99 plus bracket@ £24.99
Sea Me - £499

I think I'll stick with my octahedron for now.

 

[Greenwichman]

Most things have been said here and in earlier Forum posts on the subject of radar reflectors.

But not all Forumites are hearing the core truth: namely, a passive radar reflector in a small craft is next to useless in terms of avoiding close quarters with shipping.

I had the joy of being a professional seafarer for more than 30 years, including a decade in command. The truth is that owing to clutter (and the laws of physics) radar equipments fitted in warships and merchant ships are unlikely to detect small craft even when the later are fitted with passive radar reflectors.

Answers for small craft include: an active transponder (admittedly at some cost); an excellent lookout; the best lights you can afford (and not the LED variety); early and bold action to avoid close quarters (ie keep two miles clear of the ahead sectors of a fast moving ship if you can); an engine ready to start when in or near shipping lanes; avoid at all costs the combination of mist/fog and shipping; by all means fit radar and AIS, but trust no equipment, only your own seamanship.

IMHO passive reflectors are a scam. Not worth the cost, and simply weight and windage aloft.

 

[Slow_boat]

[ QUOTE ]

Answers for small craft include: an active transponder (admittedly at some cost); an excellent lookout; the best lights you can afford (and not the LED variety); early and bold action to avoid close quarters (ie keep two miles clear of the ahead sectors of a fast moving ship if you can); an engine ready to start when in or near shipping lanes; avoid at all costs the combination of mist/fog and shipping; by all means fit radar and AIS, but trust no equipment, only your own seamanship.

IMHO passive reflectors are a scam. Not worth the cost, and simply weight and windage aloft.

[/ QUOTE ]

Just when I was begining to think common sense and seamanship had gone out of fashion in favour of gadgets, that is the best bit of advice I have heard on this subject in a long time.

Your good health, sir. /forums/images/graemlins/smirk.gif

 

[bilbobaggins]

Thanks for that. It confirms my 'take' on the subject.

I'd like to have your experienced view of the limited use of high-intensity strobes by a small craft, in a 'risk of collision' resolution - to attract the eye of the lookout.

/forums/images/graemlins/wink.gif

 

[Twister_Ken]

Point of order

Strange how this has become a discussion about the merits of radar, and radar reflectors, whereas if the PoB had been keeping a 'correct' VISUAL lookout, three people would still be alive and enjoying great sailing weather this weekend.

Let's not forget that IF the OOW had kept the chart room curtains closed, IF he had not turned off the night time lighting in favour of white lighting, IF he had left the radar in nighttime mode, IF the lookout hadn't been wearing - effectively - tinted glasses, and IF P&O had scheduled adequate night vision adaptation time between lookout watch changes, we'd have never heard of the Ouzo.

This is a tragedy that mark I eyeball should have prevented, regardless of the vagaries of radar reflection.

 

[Bergman]

Re: Point of order

Agreed absolutely.

I would make the point that had such total reliance upon radar not been made then perhaps some or even all of the precautions you list would have been taken.

Sadly I suspect that this attitude is endemic and whether we like it or not that isn't going to change. Which leaves us with the technology issue to address.

What bothers me is that the casual acceptance of the situation - radar won't work because of clutter so its the yacht's problem - will have the effect of shifting responsibility from the ferry to the yacht. What percentage responsibility weighs against the yacht for not having a reflector that shows up on the ferry's radar?

I would bet a pound that this point is raised if all of this goes to court.

Sometimes referred to as the thin end of the wedge.

 

[Birdseye]

[ QUOTE ]
I am both concerned and confused by the part of the report suggesting that the yacht was not picked up on the ferries radar. Part of the report says that a similar yacht WITHOUT a radar reflector was picked up by VTS in Southampton during part of the investigation as far away as Bembridge.

Last weekend we motored around the Isle of Widget in company with some friends who were at times ahead and other times behind us. The ONLY time we 'lost' them on radar was when they were directly behind us .... scanner is mast mounted.

We could see EVERY other craft regardless of size.

The only difference then was that our sea conditions were flat calm and the night of the accident I think that I read that there was a F5 blowing plus attendant swell.

If this means that I am 'invisible' in a F5 then it's time to give up night sailing !!!

[/ QUOTE ]

"not visible on radar" after an enquiry of this sort canmean just what it says. who knows?

however, imagine shining a light from your own boiat and wanting to hit a small flat piece of mirror fastened to the "target". thats what a radar is like and obviously wont work as well in rough seas as in flat. you can also have a situation where the reflection from lumps like the engine cancel out those from the reflector at certain angles - sounds odd, but its basic physics.

I was recently on the bridge of a largeish container ship approaching port and I was astounded how difficult it was to spot the yachts both visually and on radar in an F5./6. the reality was that we were relying on them to get out of the way because they simply couldnt be seen 100% of the time in sufficient time to alter course.

I learned a new version of the colregs that day, and I reckon that every commercial skipper sailing a big vessel out of the south coast is reading this report and thinking "there but for the grace of god ......."


P.S. Night sailing? Its easier to be safe than in the daytime!

 

[achwilan]

To summarize this thread, and keep simple rules in mind, yachtman lambda is in the position of a toad trying to cross a motorway; so his survival depends essentially on HIS OWN skills with radar and visual plotting, and manoeuveuring accordingly. And as stated in colregs he must avoid capers apt to fool the fast incoming car which could have fortunately spotted him...
Just an interesting optimal control problem...

 

[Greenwichman]

Re: Point of order

Sadly, I agree with you about the thin edge. Now that active (transponding) radar reflectors are available on the market, a yacht that chooses not to instal one would be likely to bear part of the responsibility for any close quarters situation that develops.

I don't personally have one in my boat because I choose not to spend the money on it, but instead I manage the risk of close quarters situations by the methods suggested in my earlier post.

None of which can excuse a failure on the part of any ship to comply with the international regs for prevention of collision, which clearly place a burden on all parties to maintain an efficient lookout by all available means.

I am not a lawyer, but from the perspective of an expert witness I would comment that if it can be proven that the visual lookout were inefficient then that would be evidence of a contravention of the regs, whether or not the radar suffers from clutter.

 

[Twister_Ken]

Re: Point of order

Rule 5

Look-out

Every vessel shall at all times maintain a proper look-out by sight as well as by 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.

 

[Andrew_Fanner]

Re: Point of order

Do we seem to conclude that your budget £20 octahedral is a waste of £20? Thousands of wasted £20s. Next stage up is £120 and not, if I read it aright, much better. What about 2 x octahedra or having a bigger one? I know rock all about radar but would be very keen to see a minimum cost option as they are far more likely to be fitted. As for a powered reflector, what use is it if the power fails?

 

[Stemar]

Re: Point of order

I've no pretentions to expertise, but 2 reflectors won't necessarily, and in all conditions give a better result than one. In fact, there is a risk that the two reflections will end up out of phase and so cancel each other out at least some of the time.

Since the radar system needs to see a target for a certain amount of sweeps before it believes it's real, adding another reflector could mean it wouldn't see you at all!