Radar Reflector

[Velero49]

Which radar reflector works for you? I am looking at the Davis and the plastimo. The other are out my pice range.I am leaning towards the palstimo beacuse of its size and perhaps get two of the 2 m2 instead of one 4m2. What is your experience with your radar reflector?46

 

[Jack W]

Alternate idea

Last year I bought the RADAR flag.We tried it out as a comparison with a traditional reflector using a boat with radar on board and found that the flag was just as good (and doubles as a flag too!).We first tried it on a pole off the stern and it "painted" well.We then hoisted it up the burgeee halyard and it "lit up the screen".I'm very happy with it.

 

[Fred Ficarra]

OK, let's start an argument.

You don't need one of those reflectors hanging off the boat. A modern radar will see ducks and boat wakes. Sure, some boaters have anecdotal stories of improved reflections but as far as safety goes, it's a waste of time and effort. The key is Raster Scan. (AKA, computerized) I haven't seen an older set in,,, I can't remember seeing an older set.

 

[John Nantz]

Davis Echomaster

Being a good radar target is a really good idea in situations with low visability and sometimes fog can set in within a mater of minutes when it is least expected. Several years ago there was a test report on the various radar reflectors and the Davis EchoMaster came out on top and considering everything that is what I went with. At the time there was a small one and a large one but I went with the large one. Anyway, the significant factors to consider:Size - bigger is much better. The cross-sectional area is what really counts.Orientation: the angular surfaces need to be at exactly 45-degrees to the transmitted radar signal for a good return; hence, obtaining the rain-catch position is very important. Mine is backstay mounted using U-bolts (not provided) because the backstay is at an angle. I ran the backstay through the assembled unit, got the alignment, drilled the holes for the U-bolts, then installed.Blockage: sails can effectively block the radar signal, especially damp or wet sails. Hence your idea of having a pair of reflectors is a good one. Because a backstay mounted reflector can be blocked by the sails I plan to install two stay-mounted Plastimo tublar-type reflectors in addition to the Davis unit. I'd opt for the EchoMaster over the Platimo Octahedral type reflector becuse of the additional reflected surface the rounded edges provide.If you're planning to travel in reduced visability then another useful piece of equipment is an automatic fog horn. Helps to provide the proper required ColRegs signal while not being distracted.Davis EchoMaster link: http://www.davisnet.com/marine/products/marine_product.asp?pnum=0152Plastimo: http://www.plastimousa.com/reflector.htmHope this helps.

 

[Velero49]

No back Stay

Thanks John. I do not have a back stay so that is not an option for me. I was in such a situaton in may while traveling to NYC. The fog settled around Barnegat Inlet making the landing a bit scary. Yes, Fred with the right training you can us the radar very effectively, in fact right after I was inside the canal at Barnegat Inlet several large (over 100 feet) fisihng boats followed me into the inlet and I am sure that they had my as a target. I am concerned about the weekend boaters who do not have the experience to fine tune (gain) their radar and I want to be as big of a target as I can.46

 

[Velero49]

Ghost Ship in the fog

Can you see the ghost fishing boat/ship?46

 

[Paul Akers]

I bought an Echomaster.

I dropped my old one over the side last year, so over the winter I bought another/better Davis Echomaster on eBay. It was brand new and I got it for $37 (including shipping) for a $70 reflector. Not a bad deal.

 

[Don12364]

Tech Stuff!

Modern ship radars have ARPA (Automatic Radar Plotting Aid). This acquires "targets" (us) and plots our courses. It gives the ship's navigating officer warnings regarding CPA (closest point of approach) and TCPA (time to closest point of approach).To acquire the target their radar needs three consecutive strong responses and then, to keep on tracking, a 50% hit rate thereafter.If it does not "see" the small boat it is likely to be overlooked.Ship's masters constantly complain that yachts are difficult, often impossible to see. Whether they have their Sea Clutter turned up or their Gain turned down is a moot point.Ships do not carry radar reflectors because they ARE radar reflectors and so ship's operators are accustomed to seeing thousands of tons of iron and adjust their sets accordingly.So modern radars cannot acquire small targets with the previously accepted 2.5 sq metres of RCS (Radar Cross Section) radar reflector's responses.IMO (International Maritime Organisation) has a new spec which became effective as from June this year and this is 10 sq metres RCS over a wide range of horizontal and vertical angles (heel angles). This is FOUR TIMES the previously accepted RCS.As far as I am aware no current yacht sized reflectors can meet these IMO recommendations - nor are they likely to because IMO cannot change the physics!!We shall all need larger reflectors - an increase in size of approx 40% in linear dimensions, double the windage and triple the weight.For info the 1955 paper by Jim Corenman, Chuck Hawley, Dick Honey and Stan Honey done for WM says that the Radar Flag was, to all intents and purposes, invisible, and the Mobri devices were likewise. A wet sail is of little use either.Further, having two small reflectors can result in doubling the response when the reflections are in phase but also a zero response when they are out of phase. It is only necessary to move one reflector 15mm (0.6") to go from one extreme to the other.The only likely contender is the "See Me" an active transponder device, but which only works on "X" band (3.2 GHz). Many ships do not run their X band when offshore.Its a black art!How's your insurance?

 

[PHitchcox]

Does radar help being seen?

Hopefully this doesn't sound numb, but doesn't using your radar provide a better reflection on others' radar screens? Don't know where I came across this, but would appreciate any confirmation, or denial, that actively engaging your radar is one of the best ways, besides a large reflector, to be seen by others.Paul

 

[chuckwayne]

active radar

running your radar "may" create a noise pattern on another set nearby if the frequencies and filtering are close-but you can't count on it-a better approach is still using a large RCS reflector or an active transponder ($$$)

 

[Carl Dupre]

Davis Echomaster

A couple of years ago we were part of a 3-boat group headed for Plymouth MA in off-and-on fog and no wind. We all had radar, so we amused ourselves by comparing radar signals; two of us had the Mobri's (including us) and one had the Davis reflector. We very quickly determined that the Mobri's were next to useless. The Davis put out a very nice blip. Then a huge powerboat came out of the fog and passed all too close. At this point we were no longer amused. The minute we reached Plymouth we went out and purchased a Davis. I have also seen numerous reviews which consistently placed the Davis among the best of the reflectors.Carl and Jules/v Syzygy

 

[Velero49]

The interned is amazing

I did not know what a Morbi's was and here is what I found using google. The results by USSailing sponsored by West Marine. "The Davis Echomaster (in the "Double Catch Rain" position) and the Lensref performed the best of all of the devices tested. The Lensref has no nulls, which is a tremendous advantage in terms of being seen, but the overall reflectance is marginal. If a Lensref is fitted on a sailing vessel, it should be gimbaled or made adjustable. The Davis Echomaster had stronger peak reflectance, but also large holes, which means that a large target would not consistently be presented on a ship’s radar."I purchased a Davis Echomaster Deluxe, but the problem is where to install it and the windage issue in terms of noise. I will install it this weekend to see how it sounds in a breeze.46

 

[Fred Ficarra]

OK, here's a question for everyone with radar.

Have you ever known of another boat that your radar couldn't see? Now lets not get carried away with examples of boats that are missed because of poor 'gain' or 'tune' and let's avoid range/power examples too. If there are stealth targets out there, then let us know what your radar make and model is.  Now, for the rest of us who own radar, is anybody with experience not confident in picking up a target? The only problem mine has is seeing too much. A seagull floating, could be a boat fishing.  And all this talk about RCS does no good if someone isn't looking at the display. The 'cure' is to get your own radar and avoid 'them'. Oh, IMHO.

 

[Franklin]

Not boats but...

I know once it didn't pick up a sign (all wood sign to warn of something). I remember that clearly because I was sailing in pitch dark and watching the radar very closely and almost hit the sign...came within 4' of it.

 

[Carl Dupre]

Davis Installation

We have two flag halyards, one on each side of the boat, and we have simply dedicated one to the Davis. We were careful to mount it on the halyard to get the proper position. Heeling will put it in a less-than-optimum position, but the vast majority of times that we have been in fog (we cruised the coast of Maine last summer; lots of fog) we weren't under sail and we were pretty much upright.BTW, Fred; you may be right, but we will take any advantage that we can get, especially at the price of a Davis reflector. We can't think of cheaper insurance. Last summer headed up Penobscot Bay, in the fog of course, we heard on our radio that there was a tanker coming up our stern. We exchanged pleasantries with the tanker's bridge on the radio when he got close enough; position, intentions, that sort of stuff; and he thanked us for calling and said that we gave a nice strong signal on his radar. The Davis reflector may have been irrelevant to that, but we don't want to find out otherwise the hard way.Carl and Jules/v Syzygy

 

[Carl Dupre]

Oh, Fred.....

I pondered your last question, and I can't say that I ever personally encountered a completely "radar invisible" boat (but if there were invisible boats in the fog....who knows!) However, we can say that a good radar reflector definitely seems to increase whatever signal your boat creates. During the Plymouth trip I cited, it was 3 Hunters, two identical and the third similar, two with Mobri's and one with a Davis, and the difference in the blip was quite startling.Also, when we were conversing with the tanker bridge in Penobscot, after they commented on our good radar signature, I asked if they often had problems seeing small boats, especially fiberglass, and they responded that they very definitely did.Again, we will take any advantage we can get out there.Carl and Jules/v Syzygy

 

[Alan]

Practical Sailor..

...answered this question years ago. The cheap Davis Echomaster reflector works as good as if not better than any of the MUCH more expensive ones. It's echo return is superior to just about all of them.

 

[John Nantz]

Many "tough to spot" targets

I've encountered many tought to spot targets over the years:1. Conical-shaped nun bouys without radar reflectors,2. A huge barge for hauling shot rock constructed of timber - this was on a mooring buoy just south of Tacoma Narrows on the east side. The return signal was less than a group of, say, five baby birds.3. A fairly large older wood boat steaming the opposite direction from me along the inside passage. He didn't have his running lights on, it was a very dark night, and missed him by a couple boat lengths or less. Again, showed up less than the little group of birds.4. While crossing the entrance to Puget Sound, going from the Whidby Island shore to Port Townsend, in pea soup (about two or three boat lengths vis.) most of the tuperware boats, including some up to around 60 ft, were essentially invisible and generally not sounding the proper signals.5. While crossing the Strait of Juan de Fuca I've often encountered "the large powerboat" situation steaming along in fog with no reflector and not hardly showing up and consequently have had some close ones. Of course they know where I am because they get a nice signal on their screen!6. Alert Bay - ahhhh, this one! This is a place where the channel necks down to probably a hundred yards wide in places. We did see a signal there and it was moving along at a pretty good clip. No telling what the signal is attached to - one of those high speed fishing boats maybe? A whale watching boat zipping along with a load of tourists from Port McNeil? Turned out to be an Alaska cruise ship! These are just a few typical examples that I can come up with when dinking around with radar. It is really appreciated when people use a reflector becasue their target shows up well and they aren't just a guess (i.e., a bird, debris in the water, or a boat).Curved metal objects like masts, stantions, etc. just don't send back a good signal. Neither does fiberglass or the metal behind fiberglass.One of the problems with fog is sometimes you get the drippy wet stuff and when the sea state is choppy you try and adjust everything out and the resultant immage is just not all that great. Anyhow, that's my two cents for what it's worth.

 

[Fred Ficarra]

Thanks John, how about coming up with an extra

penny? What is your radar? What is the power, age, ray-dome diameter,,,etc? Ever had it serviced? The boys a Radar Marine set mine up wonderfully a couple of years ago. They're in Bellingham.

 

[John Nantz]

Fred...

I don't understand - if my unit can discern flotsam and birds why would I need a newer one to pick out a boat? In theory a radar really should not do a good job picking up a bird - with it's feathers it doesn't look anything like a good reflector, either in cross-sectional area nor in type of surface. So.... if a unit is good enough to pick up a few small birds then you'd think it should be able to detect a boat, right?Anyway, for what it's worth, mine is a Raytheon 10X 16-mile with 1.5kW transmit.