Sea-Me, look BIG out there
The Sea-Me active radar reflector has been around for a few years, though it’s not well known in the States. I was just reminded of it by an article in the British publication Yachting Monthly, which recently tested just about every radar reflector available, both in a lab and on the water. The Sea-Me blew the others away. By amplifying and sending back the X-band radar signals that hit it, this gizmo can make a small yacht look like a big ship. Which is exactly how I’d like to look in the Dover Straits or right outside Camden on a foggy day like this. I once wrote a column discussing this concept, along with how radar reflectors are tested and the Sea-Me. The scary truth is that most radar reflectors on the market are not very effective. The fairly large and expensive passive ones that did well in Yachting Monthly’s testing were the Echomax EM230 and standard size Tri-Lens.
Is Sea-Me FCC approved? It seems to be the most visible RTE (radar target enhancer) in the publicity sense, but as far as I can tell, all the users are in Europe. After reading about RCS (radar cross section) of passive radar reflectors, Sea-Me looks very good. I’ve only seen four disadvantages: you can’t use your own radar at the same time, it may not work with non-pulse radars, it does not work with S-band radars, and it doesn’t work without power. The comment about non-pulse radars is here:
http://www.echomax.co.uk/competing-products.htm
This site lists six active RTEs
http://www.theradarreflectorsite.org/RTE.htm
and three of those are no longer available.
There is one more for the list: Phalconet.
One of the ones listed as not-available, Activ’Echo, is a French unit which according to rumour was taken off the market because the big ships were complaining that there were too many little boats looking like big boats. But that may not be the real reason. That unit put out sweeps of the whole radar band whenever it detected a radar, as opposed to Sea-Me which just amplifies and resends the same signal it receives.
The Jotron Tron ARR also works by transmitting a sweep of the whole band.
I had purchased a see-me on the cheap at a west marine clearance sale in 2006 and eventually returned it (thank you West Marine !) due to four factors:
(a) I had regrets at the moment I was carring it out of the store … it is heavy. It was an impulse buy being 80% off list price. (most of the weight is in the cables and control unit) and I discovered the additional wiring I would need would increase the weight significantly more.
(b) The ideal placement of the unit wasn’t possible unless I placed it where it would have a significant blind spot. One of the issues was it needed to be out of the path of my radar. I could probably live with the blind spot, if that was the only issue.
(c) I came to realize the installation cost would be well over $1,500, many times the purchase price.
(d) And the nail in the coffin … I found an article in a boating magazine comparing many types of passive radar reflectors that had a side bar on active radar reflectors. It stated they are not ideal for collision avoidance in close quarters (which they defined under 1 nm I believe). As the return signal is transmited only on the frequency of the radar that painted your boat to begin with, and the units could only issue so many pulses per minute … there is a limit that is quickly reached as you are painted more frequently where the hardware cannot respond to all the sweeps and is eventually overwhelmed.
There is a current North American source for Sea-Me:
http://www.northamericanminitransat.com/Sea-Me.html
I think it must be a hard sell — the standard reflector is so much cheaper. All the tests I’ve seen put this one way above any passive reflector. But I would like to see a test which explores its limitations.
Just because your radar reflector is visible on a good day doesn’t mean it is visible when the seas are up and the weather is bad.
If you trust your radar reflector, don’t watch this:
“Ship sinks after collision”
http://www.youtube.com/watch?v=iltgAVsRliA
BTW, Ben’s PMY article mentioned above talks about the Cyclops reflector. That company has gone out of business.
Can anyone here recall an article that appeared about 2 years ago, that was generally positive about active radar reflectors but wrote about limitations they have at close ranges ?
I recall it was a sidebar to a lengthy article about passive radar reflectors.
Thanks !
I found it. Capt Phillip Gallmann is the author, and keeps this and other articles he published at http://www.theradarreflectorsite.org/
I was looking around the boatyard the other day and it struck me that non-commercial powerboats don’t use radar reflectors, as a rule. Except for the smaller ones, they do have radar. Maybe they have a reflector in their liferaft. Then I went through a magazine looking at each ad and powerboat photo and I didn’t see a single one with a radar reflector.
Looking around at sailboats, there is some variety. Lots of Mobri reflectors, which by all reports are worthless, but low windage.
So I think there is a potential market for Sea-Me. There are lots of owners who can afford it and lots of owners who don’t like an ugly, sharp-edged, high-windage item on the boat.
I think Gallmann’s comments (under “Articles & Blogs” on the above-mentioned website) are worth checking out, but he doesn’t distinguish well enough between his opinions and his facts in this case. He gets very different test results from the QinetiQ report (which is also on his website).
I’d like a second opinion.
norse wrote “I think Gallmann’s comments (under “Articles & Blogs” on the above-mentioned website) are worth checking out, but he doesn’t distinguish well enough between his opinions and his facts in this case. He gets very different test results from the QinetiQ report (which is also on his website). I’d like a second opinion.”
… I agree. I cannot reconcile his test results either. Your welcome to contact me to chat.
Dan
The Sea-Me has a very good RCS compared to other radar reflectors, but it is good to keep in mind that that still does not guarantee that someone else’s radar will see you.
These numbers vary of course, but they should give the idea:
a person 1 square meter RCS
a small boat 1 – 10 sq m
a coaster 1000 sq m
largest tankers 100,000,000 sq m
(One source says the bulk of shipping is between a few hundred and 10,000 square meters RCS.)
The point being that if a radar is tuned to show only ships, a radar reflector isn’t going to help.
If a radar is tuned to not show sea-clutter, it may not show your boat either.
Here is a radar screen showing a target with and without a RTE (not Sea-Me)
http://www.automaticpower.com/products/catalog/2b_%20Phalconet%20RTE%20Spec.pdf
It doesn’t say what the target boat is, the range, etc. but it does show a difference. But if the target boat were just a bit closer, would it be lost in the sea clutter?
I found a blog “From the Med to Finland with the help of AIS” which is extremely interesting and very well written. Unfortunately it’s in Swedish.
http://osk.nyatider.se/blogs/vintergatan/archive/2008/02/27/fr-229-n-medlhavet-till-finskaviken.aspx
He had a Sea-Me and was disappointed because he expected to appear on radar with a supertanker sized signal. His conclusions: He found his own radar to be the most reliable help. Priceless. He had some problems with AIS. It’s nice that ships have to have it because of SOLAS; too bad they don’t require them to use it. The idea is brilliant but too many ships send out inaccurate data. Normally it is a blessing. When used together with a VHF, it makes dealing with heavy shipping traffic safe. He used it a lot.
He doesn’t say, but it seems he had a Class B transponder.
There is a lot of shipping traffic in his story and a few near misses — those were the ships which wouldn’t respond to VHF or DSC calls.
One problem he had with AIS was ghost-ships. Ships that appeared on a collision course going 100 knots. He figures that was someone playing a practical joke. But then he was followed by submarines (periscope) and other military ships…
Some sail magazine should translate and publish this story.