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When (used) boats are sold, it seems pretty common that they come complete with a plethora of miscellaneous equipment. ZTC was no exception to this with one such item we received being a radar reflector. Instead of it being rigged up on the mast somewhere where it might do some good though, it sat in one of the bow lockers taking up space.

On several occasions I thought about putting the reflector up but I found no great solution for doing so. I also did a bit of reading on the subject of radar reflectors and concluded that most of the models currently available, including the one that we had on hand, weren’t all that stellar in terms of performance. I also read some arguments that said that the radar signal given off by even a “plastic” boat such as ours is still greater than the signal that any of the reflectors could produce. And so our radar reflector sat unrigged. Until now that is.

I was always under the impression that having a radar reflector rigged was optional. I think now that I may have been mistaken on this. During the RYA theory course that I recently did, there was a practice question that specifically asked if boats needed to be fitted with a reflector and the answer I was given was yes. My web search this morning netted the same answer:

SOLAS V requires vessels if less than 150 gross tonnage and if practicable, [shall have] a radar reflector or other means, to enable detection by ships navigating by radar at both 9 and 3 GHz . 

Essentially this means that if it is possible to use a radar reflector on your boat you should do so…

Even though we don’t typically sail in bad visibility, and I do believe that most competent radar operators will be able to see our boat’s signal even without the reflector up, I think we should still try to comply with the regs. Better safe than sorry.

We need to find a way secure this beast up in the rigging somewhere.


  1. “If Possible” and “if practible”……….When I went for my captains license I found that what was right 20 years ago, is still applicable, but not used. With technology the way it is today, you are correct that your boat is a bigger deflector than a radar reflector……The northeast is full of fog and cruising is done in May and June all in fog….Sailboats have the best reflection on radar……Does it hurt, no, but not needed in my opinion

    • That was my initial opinion, but what do the regs really say?

      • [Frequency coverage]: Performance requirements should apply to either active or passive radar reflectors in both 9 GHz and 3 GHz bands.

        [Stated Performance Level]: The radar reflector should have a “Stated Performance Level” (SPL), i.e. RCS, of at least 7.5 m2 in X-band and 0.5 m2 in S-band.

        [Azimuth coverage]: The RCS should be at least the SPL over at least 280° deg azimuth; not remain below SPL over any single arc of more than 10° deg – a null; and not have distances between nulls of less than 20°.

        [Elevation coverage]: This performance should be maintained through angles of heel 10° for power driven vessels and sailing vessels designed to operate with little heel [multihulls] and through 20° for other sailing vessels.

        [Mounting height]: The recommended mounting height of 4 m …should be…marked on the reflector.

        [Active RTE]: Active reflectors should conform to Recommendation ITU-R M.1176.

  2. We had a radar reflector many years ago (similar to the one you have pictured.) We had it hoisted on a small halyard to the spreader. One day, it chafed through and fell – almost hitting Suzi on the head.

    Concurrent to that incident, I had been insulating the boat. We have two layers of ‘reflectix’ sandwiching urethane insulation along most of the hull. (

    Before putting the radar reflector back up – to which (understandably) Suzi was opposed – Suzi radioed a tugboat and asked what we looked like on his radar. He came back with, “Migawd, you look like the Queen Mary!”

    Suffice it to say, we gave away our dangerous and ineffective radar reflector. (I had never heard of the regulation you quote.)

    • Having it chafe and fall was exactly what concerned me which is why I said I found no great (super secure) way to hoist it. If I do use this one, perhaps I’ll use some spectra to hang it, being careful of possible chafe points.

  3. Mike –
    Do you have radar on ZTC? If so, turn it on on a sunny day and compare the scene on the display with the one out the window. Some boats just do not show up at all.

    The larger question: why would you *not* do everything you could to be seen?


    • We do not have radar Bob so I can’t really try that.

      I agree that it makes sense to do everything possible to be seen but as I said, I found no suitable, entirely safe way to hang that reflector in the rigging and I didn’t want it dropping down on my head some day.

  4. Mike,
    The theory behind the reflector is to have this as high as possible. When seas get rough, it offers something to a radar sweep even when your hull is somewhat obscured below waves. But that may be just theory…

  5. I agree comments above. Hard to hang, chafe, tend to make a noise in strong wind, rattle when they are older, have to be hung in the most awkward ‘water catching’ position. Mine blew down in a gale a few years back. I was glad. I have not seen it in the Regs but I accept your quote.

    Modern passive, cylindrical plastic ones seem to be ineffective according to the tests.

    The only ones that get good test marks are the ‘active’ reflectors. These are powered plastic units that amplify a received radar signal and retransmit it more strongly so the originator gets a big response. Thes are quite expensive and so are not that common.

    I have never heard that plastic boats give a big response, just the opposite in fact, but if it is true, the great!


  6. Just a few comments:
    1. At least in the US, if you get run down by another vessel and make a claim against them for damages, their attorney will use your failure to abide by the regs against you.
    2. As mentioned above, it should be hung in the “catch rain” position to maximize effectiveness.
    3. Agree with the comment about the hull being invisible in a sea trough. Reflection high can only help. (think tricolor).
    4. If you do decide to keep and use it, you can also paint it black and suspend it as a day symbol while at anchor.
    5. Good idea with the spectra.

    • 1. My thoughts too.
      2. Roger.
      3. Makes sense. Not investing in a tricolor though.
      4. Not really. I can’t leave it up as a black ball when we’re not at anchor. See #1 above.
      5. Thanks. Spectra rocks.

  7. Yeah, I read the same study. The study that made me laugh was a Coast Guard suported study ( regarding sea kayaks in Maine that gave best marks to a foil hat!

    There were some other radar thoughts and links buries in this post (

    I never got to Bermuda; my back got to where I couldn’t trust it, but the bike milage seems to be helping, so…. Quien saby.

  8. andy & sonja cru-zinacatamaran - Reply

    Our friends use theirs & put it on the halyard to the spreader , but they also said in some areas where Pirates were they took it down as they didn’t want to be seen so there are good & bad ways of looking at it, & again although they had it there it didn’t stop a big tanker from moving out of there way or change course as they had to do an emergency move at night as he had not change course. & would of sean them on radar
    I think it makes no difference in many ways as you have to have someone on watch at all times any way.

  9. You guys seem to have it covered.. .
    see “Single Handed Tips” by Andrew Evans available for free here:
    for more info on the various types and where you can look for more info. In general, the Brits seem to have the best equipment because they deal with fog more than anyone else.

    • Hi Bill

      I downloaded that PDF and I thought that I had even referenced it here on this blog at some point although I just searched and couldn’t find it.

      As for Fog, glad we haven’t had to deal with it very often.

  10. Not sure if you had considered it. I was a career submariner and all the close encounters we had were with sailboats. Sailboats undersail do not make much noise, submarines rely on noise(submerged)to know what is around them.

    Sailboats and submarines share much of the same areas. Running a depth sounder in known deep water is always a good idea, lets people who may be under you, know you are above.

  11. I think having a halyard on both top and bottom will help to hold the reflector away from chafing points. Dyneema or thin wire would make sturdy halyards, and most people use the flag halyard to the spreader. I think that having a separate set-up for the reflector would both keep it away from chafe points and avoid noise.

    • Most flag halyards, or at least the ones on our boat, are meant to hold a flag, not a big piece of metal with a lot of windage. In addition, I wouldn’t even trust the pad eye that our flag halyards run through to hold the reflector in a blow. This is why, if I do rig it, I’ll replace the halyard with spectra and add guy lines off each side, holding it securely in place.

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