Do I need a radar reflector?

[Haddock1]

This question dawned on me the other day.

My boat has a radar but no radar reflector. My last boat did not have a radar but did have a cylinder reflector on the mast. I have looked around other boats in my marina and noted that those with radar did not have the cylinder radar reflector as well. Is this because if you have a radar and assuming it is on or on standby this also acts as a reflector? And if the radar is switched off (which mine is most of the time to conserve battery) does this mean I have no reflector. Probably a bit of a dumb question but would appreciate those who are in the know.

Thanks

[a64pilot]

Radar is not a reflector switched on or off as most boats do not have a Radar detector
Most Radar reflectors are minimally effective, especially the tube shaped ones. I do not have a Radar reflector myself, but if I did, it would be a corner reflector, you know the one that looks like two metal disks out together, thing is to be effective they need to be larger than most that you see.
If you are really concerned about it, like you sail a lot in shipping lanes, then look for an active reflector, they actually receive a signal and send one back out. That makes you appear to be a much larger target than a regular reflector.

All this is my opinion of course you will get others, due to one of my jobs I got quite familiar with Radar and it’s limitations, very high speed, very expensive Radar.
Most reflectors actually do almost nothing due to their small Radar Cross Section, and detectability is all about RCS.

[Breaking Waves]

a64 is exactly correct

If you want to be better seen your 1st priority is to get an AIS transceiver (eg you should be transmitting).

Make sure you have good navigation lights.

Put large floro orange patches on the heads of your sails.

Yachting size passive radar reflectors have pretty miserable performance, and an active reflector is much better - like https://www.echomax.co.uk/radar-targ...dual-band.html

[slug]

Yes

Fit a radar reflector

Don’t let people tell you that they don’t work

At sea I regularly pick up fishing gear marked with radar reflectors at two miles

[freshalaska]

Ais won’t help you to be seen on radar, which is what original poster was asking about. Won’t even help you to be seen if the other boat doesn’t have an ais transceiver of receiver. Boating in thick fog without a way of being detected is playing Russian roulette. Fog horns help if heard or you can call out a pan pan with you position and heading.
If I missed some ways I bet others can help out.

[Mag3]

yes. they work. Yes you should have one... the small tube ones that go on standing rigging are useless... mast mounted ones or, if you have the money, active reflectors, are the way to go.

a secondary consideration if you have the money is to do AIS as noted.. though that's not radar and it's not universally had, larger ships all have it and can both send and receive that signal so having this will for sure let you be seen and see larger ships which I'm sure is your objective - technical solution aside.

as noted above: "boating in thick fog without any way of being detected is playing Russian roulette".

best of luck!

Cheers,
-Justin

[rubberduck]

I agree with the fact that you should have a reflector fitted. The big cylender ones fitted to the mast are a bit better than the small cylender ones fitted to the rigging.

In the UK and Northern france where a lot of boats are crossing the shipping lanes (and traffic is busy in general) you will see most boats with the large reflectors fitted to the mast.

AIS only helps IF the boat has has AIS and your AIS is on and working. The reflector is a passive thing you can do to help. Just my personal thoughts on it.

[Breaking Waves]

Guys, neither a64 nor I said that yachting reflectors 'dont work' ... we both said that they do not work very well. You are MUCH better off with an active unit. That is not an opinion. It is a simple fact. It has been repeadily verified in numerous independent testing - like the MAIB report
. . . https://assets.publishing.service.go...ors_report.pdf

which concluded that "The testers concluded that only the Sea-Me active reflector delivers a strong enough radar return to even meet the ISO 8729 standard, and some perform so poorly that they aren’t worth carrying because they’ll only give skippers a false sense of security. "

Stan honey led another test after another incident (http://newcontent.westmarine.com/con...Tests-1995.pdf) which reaches similar conclusion

Sure get both, but an AIS transponder should be a higher priority - it is simply a generally better system. Yea sure not everyone is looking at ais, but not everyone is looking at radar either . . . . the really important targets are (mostly) looking at ais with a high priority. Dense fog will make passive radar reflector even less effective.

[freshalaska]

Yes AIS is certainly a good idea. I’ll stick my neck out a say most boats don’t have a AIS receivers. Doesn’t take a big boat to eat your lunch or ruin your day.
Good radar and to monitor it is in my opinion you best bet in thick fog for staying safe.

[Lodesman]

Originally Posted by Haddock1

This question dawned on me the other day.

My boat has a radar but no radar reflector. My last boat did not have a radar but did have a cylinder reflector on the mast. I have looked around other boats in my marina and noted that those with radar did not have the cylinder radar reflector as well. Is this because if you have a radar and assuming it is on or on standby this also acts as a reflector? And if the radar is switched off (which mine is most of the time to conserve battery) does this mean I have no reflector. Probably a bit of a dumb question but would appreciate those who are in the know.

Thanks

In addition to the above, it might also depend where you are located, as it might be legally required to have a radar reflector - such as in Canada:

Rule 40

Radar Reflectors

• (a)
  Subject to paragraph (b), a vessel that is less than 20 metres in length or is constructed primarily of non-metallic materials shall, if practicable, be equipped with a radar reflector or other means to enable the vessel’s detection by other vessels navigating by radar at 3 GHz or 9 GHz.

[Breaking Waves]

Originally Posted by Lodesman

In addition to the above, it might also depend where you are located, as it might be legally required to have a radar reflector - such as in Canada:

The full Canadian bulletin is worth reading.

It included links to some good tests, and comments about reflector size and installation (needs to be decently high and decently large). it includes the comment "There have been collisions between small and large vessels where casualty investigations have indicated that ineffective radar reflectors may have played a role in these accidents (eg the boat had a reflector but it did not increase the rcs enough to make the boat visible in the conditions)."

You have chopped off a pretty important part of the Canadian law . . . the whole 'unless' section . . .

"
Rule 40 Collision Regulations, Canada Shipping Act 2001 requires a vessel that is less than 20 metres in length or is constructed primarily of non-metallic materials to be equipped with a radar reflector if practicable, unless (i) it operates in limited traffic conditions, daylight, and favourable environmental conditions and where compliance is not essential for the safety of the vessel, or (ii) the small size of the vessel or its operation away from radar navigation makes compliance impracticable. "

And as shown by the tests and the MAIB report, pretty much none of the available yachting passive reflectors meet the ISO standard for minimum RCS (at different angles).

Again - put a passive reflector on it you want . . . .but realize it will be, only minimally effective and you would be much more effective if you used an active unit.

As to the OP's post - your radar dome is an extremely ineffective reflector whether it is on or off. Yes, it probably does increase your RCS by some small unmeasurable in the real world amount but would be so small it should have no impact on whether you think you should have some other form of system.

[Discovery 15797]

You don't require one by USCG regulation, and no a radar tx/rc does not act as a reflector.

But I was specifically asked if I had one in my most recent survey...which would imply that insurance companies might require one if the surveyor notes that one is not onboard.

Slug and BreakingWaves are both correct. They work do some degree, but they generally do not paint a consistent target, so you must be vigilant. Active units are best. The EchoMax Active-XS reflector is about $1,000. Probably worth the expense if you are in an area with lots of fog and high vessel traffic.

Passive reflectors don't have to be especially large. A flat 3' square metal plate will return a radar cross section of about 10,000 square feet when viewed perpendicular to the surface. This is the key...the best return is when the target is perpedicular...which is why passive radar devices return intermittent targets...they are small and their small plate is not always perpendicular to the radar antenna.

Fog doen't affect the effectiveness of a passive radar reflector...it is a passive device. The strength of the radar rx/tx and the rx ability to minimize clutter and noise caused by atmospheric conditions like rain, sea state, etc. may affect the ability of your radar to discern the return from a passive reflector.

Also, you should not call pan pan when maneuvering in dense fog. Maybe "sécurité, but not "pan pan." But if you're in an area where you have occasional fog and don't have radar...you probably shouldn't be underway even if you have AIS, or you should be moving 'dead slow."

[OrangeCrush]

I have radar, AIS, and a large round reflector that I haul up a flag halyard whenever it's necessary. I vastly prefer that to an expensive and bulky mast mounted one that creates windage even when it's not needed. All the other points here are good, just wanted to add my two cents in support of the small inconvenience of raising it when it's needed versus the larger disadvantage of mounting it permanently.

[freshalaska]

Yes my mistake securite would be the correct vhf call and what I do in dense fog.

[Breaking Waves]

Originally Posted by Discovery 15797

Fog doen't affect the effectiveness of a passive radar reflector...it is a passive device. The strength of the radar rx/tx and the rx ability to minimize clutter and noise caused by atmospheric conditions like rain, sea state, etc. may affect the ability of your radar to discern the return from a passive reflector.

hmmm . . . seems like a bit of a semantic quibble . . . as you agree that the return from a passive reflector will be 'more difficult to discern'. At least in my use of the English language that would make it less effective.