Radar reflectors

[Bavarian]

I am looking at radar reflectors for my 30 foot yacht.

Being totally unfamiliar with radar could you advise me at what distance would a boat fitted with radar "see" on their screen a fiberglass boat not fitted with a reflector?

Are the fixed reflectors such as "Blipper" or "Echomax" worth considering over the cylindrical units that can be hoisted in the rigging?

Thanks for your advise.

 

[Marsupial]

I examined these devices and concluded they just take up space and cost a lot.

I settled for a SeaMe and a flat packed radar reflector for £10.00 to hoist if I run out of sparks.

I know the SeaMe works, we get mentioned ship to ship all the time!

Hope this helps

 

[mickandbee]

[ QUOTE ]
I examined these devices and concluded they just take up space and cost a lot.

How?

 

[wavelet]

The UK yachting magazine test of a few years ago threw into question (grin) the whole range of commercially available radar reflectors. I seem to remember that a crushed biscuit tin was as good as the best and most expensive. I have a fat, white cylindrical thing which has been up there years and I've not been hit yet, although I've certainly been surprised a few times by ships passing close by on reciprocal headings, quite humbling in a big sea as well as in a calm.
If you can afford a Sea Me it is a good thing to have. I could only afford a Mer Veille, radar detector by French firm, Ciel et Marine and that has looked after me as a singlehander over three thousand miles. I "see" a whole lot more ships with Mer Veille than without it and sometimes it tells me about ships which I do not get to see at all. Mer Veille has red LED's to indicate the approximate bearing of a radar as it "paints" your boat. Mer Veille emits a nice little buzzing noise which becomes like a friend after a few days alone at sea. From memory, it cost just under four hundred euros inc. postage.

 

[Marsupial]

On a yacht they hang on the mast and decrease AVS, and make yet another snag for the main halyard (funny how bits of line snag on things - except you really would like them to) on a motor boat they either stick up above the radar scanner or require the whole issue to be raised. For what purpose? THEY DONT WORK!! - oh yes and they cost a lot.

Cheers


david

 

[billcowan]

I remember reading a test by the US coastgaurd
They decided that they were all totally crap.
Echomax was four times less crap than Blipper.
Blipper was half as crap as the best of the rest
The old corner cube thing only worked OK if it was a) huge - 1M + and b) if it was bolted upright to a post.
Those slim tube things you see clipped to topshrouds are totally useless.
Finally all of them were drastically less good when waving about or healed.

I would say that now with AIS big ships wont be looking for nameless dots on their screens, except in dense fog when usually it is also calm and your reflector is at its least bad.

However observing my own radar, other yachts fitted with big blobby reflectors like echomax, show up well at 5 miles, ones without or with slim tube things dont show up AT ALL, you hear their wash first!

 

[Blueboatman]

? Time to stuff the mast with crushed up folds of tin foil,perhaps?
It would stop cables from coming loose......

 

[TheBoatman]

[ QUOTE ]
Those slim tube things you see clipped to topshrouds are totally useless.

[/ QUOTE ]

I couldn't agree more!

A friend of mine is crew on a LB and they went looking for a yacht off the north foreland. The radar showed nothing even when they were 800 yrds away from the yacht. Needless to say he had one of those tubes filled with foil strapped to his rigging.

Peter.

 

[wavelet]

A Norwegian in a Folkboat sailing between the Terschilling Islands told me he was watched by the harbour master on radar and all he had was a tube type radar reflector with a stack of tetrahedral (?) reflectors inside. I found one floating by after a storm and stowed it in the chart locker. I reckon it's as good there as anywhere. The bit of the boat around the chart locker is either invisible to radar or not and if invisible then a reflection may be given by the stowed tube reflector. I also carry an electric bass guitar, two acoustic guitars and a soprano saxophone and I reckon they add up to a formidable echo at certain times.

 

[Nauti Fox]

To help you make an informed decision have a look at these sites.

Echomax

Sea me

Test

 

[fireball]

Ah - now the Soprano Sax interests me ... is it the straight or bent one?

I need to get a lot more practice in on my sax's ... but relucatant to take expensive instruments to the boat via an open tender /forums/images/graemlins/frown.gif

 

[Robin]

Dubious advice

Someone has to say it but this is a question that requires a sensible response and not a mix of hearsay and old wives tales. Safety has to be your first consideration.

Firstly SOLAS now requires all vessels where possible to carry a suitable radar reflector, the size they recommend may be bigger than most would want to or indeed can carry but we SHOULD fit the best we can IMO.

Yes there have been lots of tests over the years by various magazines and organisations trying to establish the effectiveness or not of a variety of reflectors. The results have been less than helpful IMO because in all cases there seemed to be 'other factors' influencing the results, none of the results were again IMO conclusive.

For what it is worth and based on my own experience using small boat radars over many years - FIT a reflector! We usually pick up other yachts fitted with reflectors on radar at around 4mls, more if we are really looking hard. Without a reflector the target is erratic, sometimes visible, sometimes not and it is not really consistent until say 2mls off, add a rough sea and these figures are reduced. We have had a wooden boat with wooden masts hove too in big swells off Ushant that was almost invisible on radar at 0.5ml and powerboats bows on and engines close to the waterline are like 'stealth' vessels.

As far as affecting the AVS is concerned, are you more likely to be run down or turned over? Yes exactly!

We have a Firdell Blipper fitted on the front of our mast, it does not have the X-sectional area SOLAS would like but it is a multiple array that will give a consistent return when heeled or upright. I prefer this to hoisting a fold flat type, which also work well, because it is ALWAYS there and fog is not the only time I want to be seen as well as possible. The fold flat ones also need to be hoisted in the right attitude, ie catch-rain position which requires a cat's cradle of lines top and bottom before they are attached to a halyard and the halyard has to be led to avoid chafing through on the sharp edges of the reflector, I know because I had one crash down in Lyme Bay once. French yachts also fit the fold flat ones, usually tiny ones, to the backstay so wrong way up and too small = useless. Also competely useless IMO are the Mobri small diameter tube ones you see on French boats, often even laid flat along the spreaders, they contain multiple tiny reflectors but have no area.

I have used 'IMO' many times in this reply because it is just that but I really believe you should have a reflector and that it is best if it is permanently fitted, raceboats may think differently however.

Robin

 

[chris66]

Re: Dubious advice

For what its worth, Italian maritime regulations state that you have to have a "radar reflector" fitted. No one in authority could decide what was a decent reflector so no specification was given. I know of two sailors who have stuck a Euro coin to the hull and swear to the authorities that it is an effective reflector...
Myself I see that as a waste of 66 pence and superglue and if they can't see 2 great big davits, a 45 pound CQR and lots of shining railings then a bit of plastic full of kitchen foil is not going to help matters...

 

[Marsupial]

Re: Dubious advice

There’s nothing more dubious than promoting a technology that is demonstrably flawed and inferior. How many “tests” will it take before the majority concede that in conditions where you really need them, dark, raining and rough, passive reflectors do not work, even if they manage an echo it's lost in clutter. I take my lead from a super tanker captain who laughed like a drain when he saw the claims made by the passive reflector lobby, He said in rough seas “little yachts” (45ft) with passive reflectors get lost in the clutter and (our) radar wont see you. Let’s just say I know I what I have fitted, and I KNOW it works, prior to fitting the SeaMe I had a blipper I was NEVER called on the VHF to identify my type, (usually at night). Now I am called up all the time “vessel at position . . . what is your type”, that must be safer.

Having a passive reflector is possibly better than no reflector at at all, a bit like a wooly hat vs a hard hat on a building site.

AIS

I have learned today that the “positional” information provide by AIS can be 25 minutes old, in practical terms; according to my source, “the Container Ship AIS thinks is just of the Roughs is actually the one throwing lines to the shore crew Felixstowe Port.”

Conclusion: AIS has limited utility as a RADAR substitute.

This may have been discussed on the forum before but I felt it was worth sharing.

Cheers


David

 

[BrendanS]

Re: Dubious dadvice

do you have verification of this. My understanding is that the website which shows activity is time lagged except for people who have paid for live info, but ships transmit in real time. Tho it's known some ships turn off AIS at times for commercial reasons, tho this is of dubious legal status.

 

[Marsupial]

Re: Dubious dadvice

have sent you a PM

 

[Robin]

Re: Dubious advice

[ QUOTE ]
There’s nothing more dubious than promoting a technology that is demonstrably flawed and inferior.

[/ QUOTE ]

David

You are of course entitled to your opinion as indeed am I. My point is that your advice to the world at large is to ignore SOLAS, ignore normal advice and conventional practice and that I think is not a good thing.

I based my reply on personal experience of using small boat radars over many years and observing in practice what can be seen at what ranges and out of curiosity if the target could when closer be seen to be fitted with a reflector.


[ QUOTE ]
How many “tests” will it take before the majority concede that in conditions where you really need them, dark, raining and rough, passive reflectors do not work, even if they manage an echo it's lost in clutter.

[/ QUOTE ]

Actually the conditions I am most concerned about being seen in involve FOG. I do have quite a bit of experience of being in thick fog whilst sailing, both inshore and in the shipping lanes so I feel I can comment from the small boat point of view. Now I too have had several instances where I have had VHF conversations with large vessels, one intercepted a conversation between two of us in company discussing if we were clearing a crossing ship and was able to a) confirm our position (and therefore we WERE the correct boats) and b) to tell us that we were indeed clearing him safely astern. On another occasion I called Ushant Traffic Control to ask if they had information on visibility closer inshore in Chenal Du Four, thay asked me for range/bearing from Creac'h Light and when I gave them it said they had us clearly on their radar - range 12 miles! OK big radar but would we have showed without a reflector, at that time we had a 33ft grp boat?

From my own experience using my own small boat radars, yachts WITH reflectors are visible more consistently than those without. Inconsistent radar returns are easily missed unless you are watching the screen 100% of the time which in reality is not usually the case and these targets even when seen are more difficult to plot and predict. Consider the incident last year(?) with the Moody run down in the Channel, there was never any argument that that the Moody was not SEEN on radar, only that both vessels apparently took inadequate/inappropriate action.

[ QUOTE ]
prior to fitting the SeaMe I had a blipper I was NEVER called on the VHF to identify my type, (usually at night). Now I am called up all the time “vessel at position . . . what is your type”, that must be safer.

[/ QUOTE ]

I have no doubt the SeaMe paints a picture of a bigger vessel and often begs questions as to why it doesn't act it's size. Unfortunately the SeaMe is £499, needs a power supply to run it and is not so easily fitted on smaller small boats such as the poster's. I would also think that in terms of priority I would buy radar before SeaMe, being seen is one thing, being avoided or ignored is another, I prefer to 'see' for myself.

AIS is a whole new subject and I still have reservations about it's use as a standalone device or esppecially as a radar substitute.

Robin

 

[capt_courageous]

Hi Bav
I think PBO did an article on this July 2005. They say that what you pay is not always what you get. Well worth a read as I recall.
Most yachtie sized reflectors work for what are often called X Band radars but not nearly so well for S Band radars. It is all to do with wavelength/size of antenna etc. X is what yachties have. Ships often have both X and S. They tend to use X inshore and S further out. So be carefull about any performance claims that don't specify the Band.
I mostly just wander about in the Solent in broad daylight so just make do with a very popular model which fails every real performance test. If you want to dice it cross Channel at night do as much research as you can and don't try to save money. That tanker only has to hit you once.

 

[Marsupial]

Re: Dubious advice

No dont IGNOR SOLAS but SOLAS = "wooly hat" not much better than nothing, ie DUBIOUS ADVICE.

Fog should not present a problem for any radar, its not often rough and raining in fog, more often glassy smooth - my radar picks up fishing floats in those conditions. VHF assisted collision is another matter, as is inappropriate action by any party - but anything that improves either your or anothers ability to "see " must be safer.

Fitting to a small yacht - Seame would be much easier to fit than a blipper - my first yacht was 30ft.

Each to his own in the end, but little bits of bent aluminum stuffed in plastic boxes are dubious technology, to make them work at all angles of heal they have to be a compromise at any angle of heal. Sorry people this stuff is crap, I stand by my original evaluation of this tacky technology.

I've been peering into radars for 30 years, the technology isnt perfect but to rely on passives to improve your csa is foolhardy when better solutions are available. I carry a flat pack to comply with SOLAS and to provide redudancy for the lack of latency in the active solution. But overall, technolgy has on this accasion has raised the game.

 

[Robin]

Same Hymn Sheet

David

Now we are agreed! I just wouldn't want to advise anyone to ignore SOLAS.

However I remain convinced (from my own experience) that the Firdell types give a more consistent return even if not at such a big range. This is very obvious in French waters where the locals generally either have no reflector, silly Mobri ones, or tiny octahedrals mounted point up on the backstay, you could almost guess the nationality of approaching vessels on radar as nearly all Brits were clearer and had Blippers.

Yes we can see pot markers too in flat calms but only if you are on close range scanning, seagulls are good too!

Robin