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Old 11-11-2008, 15:30   #1
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RADAR REFLECTORS

Hi all
Looking for some advice regarding size and shape of radar reflectors that work. Iwould like to keep the size to a minimum but I realize it has to be a certain size to work.I dont know what the return signal from my boat would be. It is a 11m fibreglass bridgedeck cat.I have radar .I am leaving Brisbane in approx 2 weeks heading down the East coast for Adelaide and want the best radar signiture possible.Any other ideas would be appreciated

cheers Steve
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Old 11-11-2008, 15:40   #2
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Have you seen this site? May help a bit.

1995 Radar Reflector Test
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Old 11-11-2008, 16:10   #3
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Time after time the Davis aluminum reflector has tested better than many of the expensive high tech models. Correct placement and installation is important.
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Old 11-11-2008, 17:08   #4
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There was a very interesting report commissioned by the UK MAIB after the yacht Ouzo was run over by a ferry (try search - report is 2MB, too big to post). Report concluded that none of the passive reflectors complied with applicable standards (Tri lens was best) and the results were very poor for the Davis and Plastimo tube type. Also of note was how much performance degraded with a relatively small angle of heel

The MAIB Investigation Reports, concerning the Yacht Ouzo are at:
http://www.maib.gov.uk/publications/.../2007/ouzo.cfm

Which includes the Radar Reflect Report at:
http://www.maib.gov.uk/cms_resources/Radar%20reflectors%20report.pdf
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Old 11-11-2008, 17:41   #5
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Quote:
Originally Posted by Steve Thompson View Post
Hi all
Looking for some advice regarding size and shape of radar reflectors that work. Iwould like to keep the size to a minimum but I realize it has to be a certain size to work.I dont know what the return signal from my boat would be. It is a 11m fibreglass bridgedeck cat.I have radar .I am leaving Brisbane in approx 2 weeks heading down the East coast for Adelaide and want the best radar signiture possible.Any other ideas would be appreciated

cheers Steve
I recommend this link

and this thread
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Old 11-11-2008, 17:45   #6
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Speaking as someone from the foggy state of Maine with literally thousands of hours spent in the fog all I can say is YES!

Radar likes right angles and flat surfaces to reflect signal back. Rounded masts are not a good reflector. While many boats do show up without a reflector the target definition and target itself on screen is usually quite small and can be mistaken for a lobster pot or buoy or sea clutter. Make your boat show up on someones radar screen and definitely buy a reflector..


Oh never mind I'll just show you. I took this photo a few months ago at my mooring during the set up and install of my new Garmin HD radar that replaced a Raytheon CRT unit.

The target labeled in red as "C-30" is a Catalina 30 with no radar reflector. The much bigger target labeled in green as "M-28" is a Morris 28 with a radar reflector. Hopefully seeing is believing...!

LOOK BIG!!



P.S. ANY reflector is better than no reflector! I have yet to see a boat with any reflector that I did not pick up on screen. I have come across many boats with no reflector that I never saw because the target returns were inconsistent or appeared a sea clutter..
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Old 12-11-2008, 08:45   #7
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Tri-Lens, period. Best unit of passive reflectors, especially for a multihull. West Marine stores, and others, carry them. They are not cheap. See Practical Sailor, August, 2001 for corroboration.
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Old 12-11-2008, 09:01   #8
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I forget what brand reflector this is. It was attatched by the P.O. in Europe. When we call to see what kind of signal we are giving off. We always get a good positive. Maybe it's because we sail a brick, or it's the reflector? It's attatched above the lower strbrd spreader.
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Old 12-11-2008, 12:41   #9
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That's either a Mobri, or a Mobri like Plastimo, which got lousy reviews in the Reflector Tests. These only seem to work well if they are vertical hence most people--like us--that use them have them mounted on the angled portion of the rigging, preferably one on each side if the mast so that at least one is vertical most of the time. While they rec'd lousy ratings, other boats we've asked to report on our radar return have generally indicated we were quite visable on their screens including the Key West Express Ferry that reported they had picked us up at about 10 miles (which they covered in less than 15 minutes!).

FWIW...

s/v HyLyte
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Old 12-11-2008, 12:48   #10
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I guess that means I sailing a brick? lololololol
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Old 12-11-2008, 14:36   #11
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I guess that means I sailing a brick?
Well, as long as you boat doesn't heel ... oh, that's right ... catamaran
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Old 12-11-2008, 15:07   #12
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There needs to be a three sided, 90 degree shape where the three sides are exactly 90 degrees to each other somewhere in the reflector so it does not matter how much the boat is heeling because with this shape, the angle in will be exactly the opposite direction back out....regardless of which angle it hits the shape. Exact 90 degree angles and the larger the better.

Most buoys have this shape at the top.
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Old 13-11-2008, 03:16   #13
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There was an article in Yachting World early this year about a racing yacht sinking between Hawaii & California (whale strike) , remained afloat with decks awash for quite some time - it had a carbon fibre main and the author noted that the Coastguard guys said this gave one of the best radar returns they had ever seen! Food for thought.
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Old 14-11-2008, 16:41   #14
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I agree with buying any reflector is better than none. And RADAR loves a right angle. I've spent 25+ years in the USN doing open ocean searches with airborne RADAR. And while we may or may not find you without a reflector, why not increase the odds. As for shipping avoiding you, remember the RADAR operator has to be looking at his screen!?! better for you to see him and avoid.
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Old 14-11-2008, 19:51   #15
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Report by QinetiQ:
“Performance Investigation of Marine Radar
Reflectors on the Market”
This study was commissioned by MAIB as a result of the loss of the yacht
Ouzo (see investigation report www.MAIB.gov.UK). The work, which has
been carried out by QinetiQ, Funtington, is designed to better inform
yachtsmen of the most appropriate choice of radar reflector for their craft from
among those currently being produced. The quality of the study has been
independently assessed for MAIB by two other experts in the field.
http://www.maib.gov.uk/cms_resources/Radar%20reflectors%20report.pdf
This research was published last year. Very revealing details.
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