Radar Reflectors - Which to get, where to mount?-gctid396927

[TenMile]

Hi all,

Transport Canada has now but settled the debate surrounding Radar Reflectors and has made them mandatory for most circumstances:

Radar reflectors are required for boats under 20 m (65'7") and boats that are built of mostly non-metallic materials. A radar reflector is not required if:

the boat operates in limited traffic conditions, daylight and favourable environmental conditions, and where having a radar reflector is not essential to the boat's safety; or

the small size of the boat or its operation away from radar navigation makes having a radar reflector impracticable.

Anyhow, I now need to get one and mount it. I need to figure out which unit to get -- I've found this document to be helpful: http://www.theradarreflectorsite.org...PassiveRTE.pdf -- for my uses, it looks like the Davis Echomaster is a decent choice as power boats don't heel over for long intervals and that the Mobri style units don't work well (see page 31 of this report: http://www.maib.gov.uk/cms_resources...s%20report.pdf).

Interested in how others have mounted their units of choice. In particular, the Davis Echomaster units. On the Westmarine website, the reviewer of the Davis Echomaster indicated it mounted it under the dash on his flybridge. That's an interesting idea as the units are a bit of a challenge to mount -- but I'm wondering if that mounting position reduces the performance of the unit itself? Any thoughts and photos would be appreciated.

[Guest]

US Sailing has a nice write up on them. http://offshore.ussailing.org/Assets...ctor+tests.pdf

[TenMile]

After posting, I dropped by my local marine shop and got myself a Davis Echomaster. They make a rail mount for it and I think I have a good spot to mount it on or under my awning.

I will take some pics once it's done.

[Guest]

I would like to see the picture...

[CaptTom]

I picked up one of the reflectors that the commercial fishermen use on their high fliers.

I got it at a local fishing supply store. Paid a fraction of what the "yachtie" ones cost.

Others who have seen me on radar say it lights up the screen.

[JimMc]

CaptTom wrote:
I picked up one of the reflectors that the commercial fishermen use on their high fliers.

So what brand was the one you installed ?

[TenMile]

So I ended up getting one of the Davis EchoMaster units with the surface mounting connection. So that it doesn't interfere with my radar unit, I actually mounted it under the radar arch under the new awning that I made. Works well and keeps it out of site.

[img]/media/kunena/attachments/vb/705368=29858-photo.JPG[/img]When I came to the boat today to get ready for a trip, I noticed a bunch of mud in the cockpit. Odd thing -- initially I thought I had a mink or otter hanging out -- but a closer look, and it looks like one of the resident martin or swallow families also like the new installation of this reflector. Crazy thing is it's only been on the boat one week! They are going to get a big surprise when I move the boat to Bamfield tomorrow.

[img]/media/kunena/attachments/vb/705368=29860-photo.JPG[/img] Attached files [img]/media/kunena/attachments/vb/705368=29859-photo.JPG[/img]

[Guest]

My .02,

I would get the reflector up as high as practicable. Due to a phenomenology known as multipath, radar can't "see" down quite as close to the water as a person or a camera visually.

Secondly, a power boat has significant RCS as the radar beam can see through the fiberglass shell of the boat down into the engine compartment and galley area where there are lots of things to reflect the radar energy. Those reflectors in the article will not do anything unless they have a large RCS than the boat (easier if they are high up. They are a significant improvement for sailboats because one can hoist them up the mast.

Thirdly, Radar operators all adjust the controls to their liking. They may turn down the gain to make the sea clutter go away, but that will also mkae small boats go away. So having a say +10 dbsm reflector aboard would not give me a warm & fuzzy feeling that all the big ships can see me.

Higher RCS is gained by making the reflectors bigger. The ones on the channel buoys are a good example. Those are made with trihedrals with about 15-20 inch radiusses - Probably have an RCS of +20 dbsm or higher. Something like that mounted above the radar dome would work real well.

In the web site below an internal radar relector with an RCS of 10M2 is shown with dotted lines in the outling drawing of the SB-104 fast water buoy on page 3.

http://www.tidelandsignal.com/web/html/data-sheets/aug-2008/MULTI-PURPOSE-BUOYS-R5.pdf

Don

[TenMile]

I understand that higher is better -- but in reality, unless I put it up on a pole or tower, we're not talking about a significant difference in height. As it is, it is currently mounted about 8ft above the waterline. If it went on top of the arch it would be maybe 9ft and this way it doesn't interfere with MY radar so I figured the trade-off was worth it.