Mounting a Radar Reflector

Stu Jackson · Jun 16, 2009

Good idea

We did this for a temporary rig for an ocean trip. No reason you couldn't zip tie it to the top of the forward lower up at the tang at the mast.

Rick D · Jun 16, 2009

Above The Spreader

Mine is mounted just above the first spreader with monel wire. It has been there for at least ten years, probably 15.

Rich Stidger · Jun 16, 2009

I have the larger size and I have attached it just above my second spreaders using small screw-type hose clamps. I would not use wire ties due to the UV degradation of them. I know that there are some black ties that are resistant to UV, but I felt that security of the metal clamps was better.

FWIW, I had water intrusion in my reflector after a year and I drilled a 3/16" hole in the bottom cap to allow any water to drain. I don't take it down over the winter and I didn't want a freezing issue. Maybe my reflector was not sealed as well as it should have been, so your mileage may vary.

sailingdog · Jun 16, 2009

Just be aware that the Plastimo radar reflector isn't very good compared to some of the others in terms of showing up on radar. Also, the reflector really needs to be mounted as close to vertical as possible for best results. If you're going to use cable ties to mount it, use the black ones, as IIRC, they have the best UV resistance. Personally, I think using a line and lashing the line to the shroud would be better than using a cable tie.

Rick D · Jun 16, 2009

"Just be aware that the Plastimo radar reflector isn't very good compared to some of the others in terms of showing up on radar".

Based upon actual experience, I don't disagree. But, it is still a meaningful improvement. And, I consider it like a life preserver: the very best one is the one you wear most. This offers minimal windage and weight and you mount it and forget it.

sailingdog · Jun 16, 2009

Bob—

The Davis Echomaster Deluxe is a far better unit, and less expensive too boot.

I use it on a halyard that goes to the upper spreader on my rig, and there are two blocks mounted to the underside of the spreader, which allows the radar reflector to hang without chafing the halyard. I leave it up 95% of the time—taking it down for bad storms when I'm not sailing.

The trip to Nantucket is a good one.. but keep an eye on the currents, especially when going through Woods Hole, and watch out for the fog and ferries.

guest · Jun 16, 2009

Mobri / Plastimo do not perform well.

SD explained it.
Here's a link to some of the testing that has been done - http://www.ussailing.org/safety/Studies/radar_reflector_2.htm#Mobri
You would be much better off and safer using one of those foil covered cardboard ones that you hang in the double catch rain position. You would have saved a lot of bucks too.

chuckwayne · Jun 16, 2009

Don't use the cable ties unless it's really temporary. My dealer installed mine with cable ties (I didn't know) and they came off-could have hit someone or something....Lash or clamp it in place properly. The larger size (Rich's setup) is much better than the littleones-If you can, return it and get the davis-we've done tests, and they are much more effective.

Don12364 · Jun 17, 2009

Doesn't Matter How You Hang It

or even whether you hang it at all.
Every report I have read states this type of reflector has no detectable response at all.

See US Sailing report:- http://www.ussailing.org/safety/Studies/radar_reflector_test.htm

sailingdog · Jun 17, 2009

Considering that the 4" version did poorly, I'd hate to think how well the 2" version does. IMHO, getting the 2" plastimo/mobri radar reflector is a poor idea, since it really does nothing to increase your radar profile significantly—and can lead to a false sense of security. The Davis Echomaster Deluxe is less expensive, and has a much greater radar return generally.

Maine Sail · Jun 18, 2009

sailingdog said:
Just be aware that the Plastimo radar reflector isn't very good compared to some of the others in terms of showing up on radar. Also, the reflector really needs to be mounted as close to vertical as possible for best results. If you're going to use cable ties to mount it, use the black ones, as IIRC, they have the best UV resistance. Personally, I think using a line and lashing the line to the shroud would be better than using a cable tie.

Tests schmests..... In my own real world experience I would honestly say that I have rarely not seen a boat with ANY reflector yet missed lots without reflectors. Sure, there is a "range" of performance but even the worst performing radar reflector, when properly used, I find works better than none at all. It's not like we don't get to use our radars much up here in Maine either...

Roger Long · Jun 18, 2009

Maine Sail said:
I would honestly say that I have never not seen a boat with ANY reflector...

Now, how are you sure that boat you didn't see didn't have a radar reflector?

I'm curious about the rain catcher vs up and down orientation of the standard round Davis type of reflector. This seems like a good subject for one of your photo essays. I would be glad to give you some help with it sometime.

sailingdog · Jun 18, 2009

Yes, but why pay MORE money for a radar reflector that is CLEARLY LESS EFFECTIVE??? BTW, I was basing my statement on efficacy on both tests and RW experience using radar.

Maine Sail said:
Tests schmests..... In my own real world experience I would honestly say that I have never not seen a boat with ANY reflector and missed LOTS without reflectors. Sure there is a "range" of performance but even the worst performing radar reflector, when properly used, I find works MUCH, MUCH better than none at all. It's not like we don't get to use our radrs much up here in Maine eitehr...

Maine Sail · Jun 18, 2009

sailingdog said:
Yes, but why pay MORE money for a radar reflector that is CLEARLY LESS EFFECTIVE??? BTW, I was basing my statement on efficacy on both tests and RW experience using radar.

I'm basing it on boats I've SEEN. When I see them come out of the fog one of the first things I do is look to see if they have a reflector. If I never saw a boat I don't know if they had one or not cause I never saw it. The bottom line is that nearly every boat I have seen pop out of the fog within sight that I have also picked up on radar ahead of time has had a reflector, any reflector. I have often never picked up boats on radar that simply pop out of the fog, "honey I'm home"

, and guess what, more often than not they don't have any reflector at all..

I have two types on board a Davis and a Mobri. The Mobri is always up there which provides a greater safety factor than forgetting to hoist my Davis. In thick fog I run both. I have spotted tons of boats boats with Mobri reflectors but do agree that the Davis shows up as a larger target.

Here is an actual photo of two boats, one with a radar reflector, and one without. I will have to check later today to see what reflector the Morris uses, can't remember. The bottom line is if any reflector is being used it is better than none at all. I do see more people actually USING Mobri's than I do other styles, perhaps because they are easy to leave up. More often than not when sailing on OPB's, in fog, the reflector is left as an after thought in the lazarette. No matter how good it is it won't do much good if it is not hoisted..

sailingdog · Jun 18, 2009

I leave my Davis Echomaster up most of the time, except if we have a storm coming in. It is hoisted on a halyard that was setup just for the radar reflector, which has two blocks mounted about a foot apart on the bottom of the top spreader, to prevent the refelctor from chafing the halyard.

chuckwayne · Jun 18, 2009

like maine sail, we did some informal tests in our rare maine fog during our annual Maine Hunter Sailing Association flotillas. I agree any reflector is better than nothing, but.. Escape showed up better with the Davis than with 2 of the small Mobris, and much better with the medium size tri -lens. Once the mobris fell off, we installed the tri-lens on the mast-I'll report back after we do some testing. As maine sail said, anything up is better than a reflector in a locker

Don12364 · Jun 19, 2009

Radar Reflector Performance

Now that we have the attention of the experts I thought it might be appropriate to toss this into the ring.

After the assumed running down of a small yacht on a clear night by a ship - and the loss of three lives, the UK govt department dealing with such matters did an analysis of the probability of a yacht with a reflector being seen by a ship's X band radar.
The weather conditions were a brisk breeze but nothing approaching heavy weather.
At no time did the ship's radar 'see' the yacht nor was there any record on the ship's voyage data recorder. The lookout did not see the yacht's nav lights until 300 yards range and the yacht then passed close down the ship's side. It was not established whether a collision occurred. The ship did not stop not did it call the Coastguard. The captain is now in jail.

The yacht was understood to be wearing a Davis reflector in the double catch rain position and by common agreement the Davis is amongst the best reflectors for yachts.
The attached graph shows that regardless of reflector area there are distances where the yacht would have zero probability of appearing on the radar screen. Most notably at 2 miles and 4 miles (6 minutes apart at 20 knots). So if this was when the OOW looked at the screen the guys were as good as dead already.

Roger Long · Jun 19, 2009

Donalex said:
The attached graph shows that regardless of reflector area there are distances where the yacht would have zero probability of appearing on the radar screen.

Wow. Very sobering. In my very limited experience of watching targets approach on my new radar, I seem to have observed the same sort of nulls. Some targets appear far out, disappear, and then reappear closer in.

I wonder what causes this and if it is specific to radar reflectors. I'm seeing a case developing here that two radar reflectors in different positions or perhaps two different kinds of reflector could be far more effective than one of any type.

Mounting a Radar Reflector

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