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Radar reflector questions

2388 Views 18 Replies 15 Participants Last post by pdqaltair, May 6, 2014

matthewwhill

Discussion Starter · May 5, 2014

Any recommendations for radar reflectors?

I have read descriptions of people mounting it with a bridle on the backstay.... How does that work?

1 - 19 of 19 Posts

bristol299bob

· #2 · May 5, 2014

If you have room for the main to come around without chafing on the reflector, I think the backstay would be fine. I'd hate to watch/hear the main drag across that reflector though, on every tack or gybe.

I believe traditional location is on the spreader.

I have 2, 3-point bridles for each reflector. the bridles attach to the top and bottom of the reflector and ensure that the reflector remains in the proper orientation (so called "catch water" orientation). the 3 points of the bridle are joined to a swivel so the whole mess can rotate about the axis.

desert rat

· #3 · May 5, 2014

For maximum reflection it needs to be as high above the water as possible and as well insulated and far away from other metal as possible.

dabnis

· #4 · May 5, 2014

matthewwhill said:
Any recommendations for radar reflectors?

I have read descriptions of people mounting it with a bridle on the backstay.... How does that work?

We had a large steel diamond shaped multi sided reflector high up on the mast of the boat below. After nearly being run down by a ship one night I don't know if they either:

1. Didn't see us on their radar

2. They weren't watching their radar

3. Our reflector didn't print on their radar.

They never gave us any blasts from their horn/whistle, nothing.

I think about the only way you would know how effective your reflector is would be to have a friend with radar track you. Or, maybe call a commercial vessel near you and ask them if they see you.

Paul T

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matthewwhill

Discussion Starter · #5 · May 5, 2014

Hmm.. can someone attach a picture of this bridle arrangement. My brain is not powerful enough to comprehend.

IStream

· #6 · May 5, 2014

I'd buy a Class B AIS Transceiver before I bought a reflector. Not only will you be more visible, but you'll be able to call bridge-to-bridge by name using your DSC VHF if someone's getting too close for comfort.

capttb

· #7 · May 5, 2014

I use the cheap octahedron ones flown from the courtesy flag halyard on starboard spreader. I have had radio communications from commercial vessels confirm that I was a good target, one had followed me into a fog "WALL" and I wanted to make sure he didn't run me over.

SailingJackson

· #8 · May 6, 2014

Practical Sailor did some testing. My recollection is that most of the radar reflectors were sort of OK, even the cheap ones, but almost all of them showed dramatic reductions in the effectiveness when they were tilted a bit. If you want to be seen while you're heeling a bit, one stood out from all the others. The Rozendal Tri-Lens Radar Reflector still has a good reflection even when the boat is tipped.

I work with an ex-navy guy. He said the reflectors were amazing when they worked. The little sailboats showed up like a navy destroyer when they had a proper reflector.

GTJ

SVAuspicious

· #9 · May 6, 2014

To my knowledge there are two publicly available scientific assessments, both of which point to the Tri-Lens as substantially better than any alternative.

http://www.maib.gov.uk/cms_resources.cfm?file=/radar reflectors report.pdf

http://www.theradarreflectorsite.org/Articles/ComparingPassiveRTE.pdf

Practical Sailor came to the same conclusion in less scientific but still relevant testing.

Reactions: 1

capta

· #10 · May 6, 2014

dabnis said:
We had a large steel diamond shaped multi sided reflector high up on the mast of the boat below. After nearly being run down by a ship one night I don't know if they either:

1. Didn't see us on their radar

2. They weren't watching their radar

3. Our reflector didn't print on their radar.

They never gave us any blasts from their horn/whistle, nothing.

I think about the only way you would know how effective your reflector is would be to have a friend with radar track you. Or, maybe call a commercial vessel near you and ask them if they see you.Paul T

Having operated vessels on both sides of this question, I will not have a radar reflector on my sailing boat.
If a small craft has a reflector that produces a return equal to a 300+ foot ship, but is invisible to a conscientious watchstander after several attempts to visually identify this 300 foot vessel, then he might chalk it up to a "ghost" in the radar and ignore that contact completely, from then on.
My take on things like radar reflectors, in fog less areas, is that it is my job to keep my eyes out for all other vessels, not leave the responsibility up to them to identify and avoid me.

JonEisberg

· #11 · May 6, 2014

capta said:
Having operated vessels on both sides of this question, I will not have a radar reflector on my sailing boat.
If a small craft has a reflector that produces a return equal to a 300+ foot ship, but is invisible to a conscientious watchstander after several attempts to visually identify this 300 foot vessel, then he might chalk it up to a "ghost" in the radar and ignore that contact completely, from then on.

I don't know, I'll happily take my chances painting a brighter picture, rather than a dimmer one, on someone else's radar screen... Or, possibly being mistaken for a larger vessel, than a smaller one

JonEisberg

· #12 · May 6, 2014

IStream said:
I'd buy a Class B AIS Transceiver before I bought a reflector. Not only will you be more visible, but you'll be able to call bridge-to-bridge by name using your DSC VHF if someone's getting too close for comfort.

Well, except for the fact that an AIS w/transponder might easily run $800 more than a Tri-Lens, and that - at least for the time being - there are FAR many more boats out there running radar, than are transmitting AIS...

Maine Sail

· #13 · May 6, 2014

JonEisberg said:
Well, except for the fact that an AIS w/transponder might easily run $800 more than a Tri-Lens, and that - at least for the time being - there are FAR many more boats out there running radar, than are transmitting AIS...

Yeah come to Maine where the fog is real and the boats transmitting AIS are less than 1%......

You could not pay me to not have a radar reflector in Maine, but then again I have only been using radar in the fog, in Maine, for 30+ years... I actually run my radar in clear weather too, just good practice, so I get to see the results, in the real world, with my radar, of how reflectors really work. Are reflectors perfect? No, but for the $40.00 you are simply foolish to sail aruond Maine and the Maritimes without one...

This boat had no reflector, painted no radar signature to speak of other than some noise, not using or monitoring VHF, no running lights and was not running fog signals..

This is what he looked like on radar he is the little red spec just above the 18' sounding:

BTW the two boats showing up clear as day, dead ahead of us to port and starboard, were both using radar reflectors and both were under sail like the invisible boat behind us.......

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JonEisberg

· #14 · May 6, 2014

SVAuspicious said:
To my knowledge there are two publicly available scientific assessments, both of which point to the Tri-Lens as substantially better than any alternative.

http://www.maib.gov.uk/cms_resources.cfm?file=/radar reflectors report.pdf

http://www.theradarreflectorsite.org/Articles/ComparingPassiveRTE.pdf

Practical Sailor came to the same conclusion in less scientific but still relevant testing.

I've viewed my little tub with a Tri-Lens from another vessel's radar at anchor up in Maine, and she seemed to be painting a very strong image, to my eye...

Before the Tri-Lens, the gold standard among passive reflectors was the previous Lunenberg device called a LensRef... Never gained much popularity, it was quite expensive at $400+... But it could easily mounted to be gimballed, a big advantage when heeled... I saw one recently in a consignment shop at NEB up in Newport, listed for something like $35, that would have been a pretty good deal... These Lunenberg devices are pretty heavy, however, and really require a secure mount... You're not gonna be hanging them from some flag halyard, that's for sure

Leocat66

· #15 · May 6, 2014

Always have one up while cruising, too much barge traffic along the Gulf Coast to be without one. Were we to go south from here, down below Belize or so, we would not run one at all. Pirates too use radar making one an easy find.

CaptainForce

· #16 · May 6, 2014

desert rat said:
For maximum reflection it needs to be as high above the water as possible and as well insulated and far away from other metal as possible.

I need some help with this. I fully understand the direct relationship with height and effective function, but I don't understand the relation to nearby metals or insulation.

We are coastal cruising and especially enjoy presenting a clear target north of the Chesapeake and on to Maine.

So, what about this nearby metal conflict? I do not see it as a factor unless the metal occludes the reflector.
We've done well with this placement on our ketch.

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IStream

· #17 · May 6, 2014

JonEisberg said:
Well, except for the fact that an AIS w/transponder might easily run $800 more than a Tri-Lens, and that - at least for the time being - there are FAR many more boats out there running radar, than are transmitting AIS...

Point taken. However, the OP is in Seattle and so am I, so we might share a primary concern about commercial traffic. Here in Puget Sound the shipping lanes cover a large fraction of the navigable space and the freighters bear down at 30+kts. You can be run over on the clearest of days before you even know they're on top of you. All those guys are running AIS.

BluemanSailor

· #18 · May 6, 2014

On my last boat and present boat I have a Mobri reflector at my spreaders. My last boat I did a transAtlantic crossing, Bristol 32, I was approaching the coast of Portugal when I saw a large sailing vessel approaching me. 70ish Oyster - came within 100 feet of me- asked him if all was ok, he said he wanted to see how large a boat I was as it turns out my radar signature was huge. I said thanks and we went on our way.

Nothing like real world example-- I'm not a fan of boating magazine equipment " TESTS"

pdqaltair

· #19 · May 6, 2014

An extensive 3rd party study. Covers many types and the effect of heel.

http://offshore.ussailing.org/Assets/Offshore/SAS/2007+Radar+Reflector+Test.pdf.pdf

And this Coast Guard sponsored test that concludes a tin foil hat is best (they were discussing kayakers, and the tinfoil hat was mounted high with rational angles).
http://www.seagrant.umaine.edu/files/pdf-global/05raref.pdf

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