Radar reflectors and you....

[dave6330]

Camaraderie and Sailingdog: Good copy and thanks for the sound advise. I'll look into an Echomaster this Spring. Still planning on PWS this Summer - God Willing. Have a very Merry Christmas!

Dave

[sailaway21]

A note of further amplification.
S-band, 10cm, radars are not good at picking up small craft and small objects regardless of constuction. Buoys, periscopes, sailboats, and even steel hulled fishing boats fit in this category as well. The same properties that allow it to "punch" through rain squalls allow it to miss these targets. The USCG has done quite a bit of study on radar reflectors and their buoys are so equipped. To date, they have been unsuccessful at producing a passive reflector that paints well on the 10cm radar. Hence the use of racons and ramarks, which are designed to paint the 10cm radar with a distinguishing mark.

X-band, or 3cm, is the radar that your radar reflector will usually paint the best. On a sailboat, or small buoy, we are talking about an increase in detection from approximately 2 miles to 5 miles with anything further being gravy, practically speaking. Given that the sea clutter on a 3cm set may easily extend outwards to 2 miles, the increase in detected distance ain't chopped liver.

None of the devices test out accurately in lab conditions although pentahedral and octahedral shapes seem to work the best. The best of designs all fall short of reliability in an actual seaway, but all beat having nothing at all. The motion of your boat makes a consistent return, even on a 3cm radar, virtually impossible.

I wouldn't discourage anyone from the purchase of a tri-lens but would not consider anything but a mast mount, as high as practicable. The Davis has as good a record as any, which isn't saying much, and I'd endorse it's use. With all such devices, there is no substitute for size-which is exactly where we started in discussing the problem in the first place isn't it?

The advent of active radar reflectors, or transponders, at reasonable prices and mounting options should be an area of intense interest to us all.

[MiVelero]

It appears the US gov thinks they are worth having.
I wonder how much they paid for this one?

http://www.sailnet.com/photogallery/...le=3098&size=1

[mikeedmo]

I've read in a number of studies that if you actually have a radar system on board that the radar antennae itself reflects better than any of the passive systems we're talking about. Makes sense to me, but I'm going on my 1970's F-4 radar, flir, tizio experience... I'll be curious to benefit from the wisdom from fellow sailnetters!

[sailingdog]

Offshore, having the RADAR reflector as high as possible makes sense, however I don't believe that is the case when the boat is inshore. WHen the boat is inshore, it is probably better to have the RADAR reflector mounted about 16' above the waterline. If you have it mounted much higher, some of the smaller powerboats and fishing boats may not get a return off of it at the shorter distances you'll generally encounter them at.

Originally Posted by sailaway21

...I wouldn't discourage anyone from the purchase of a tri-lens but would not consider anything but a mast mount, as high as practicable. The Davis has as good a record as any, which isn't saying much, and I'd endorse it's use. With all such devices, there is no substitute for size-which is exactly where we started in discussing the problem in the first place isn't it?

The advent of active radar reflectors, or transponders, at reasonable prices and mounting options should be an area of intense interest to us all.

[dave6330]

Originally Posted by sailingdog

As a caveat—you want the Deluxe Echomaster, which not only comes with the hardware required to hoist it on a halyard, but is also of a larger diameter than the standard Echomaster, and generates a greater return as a result.

OK - I have rod rigging on CIRRUS - will the Deluxe Echomaster's mounting hardware allow for easy installation on the shrouds rods? Starboard or Port (or does it matter)?

V/R

Dave

[petegingras]

i've utilized the radar reflector for the past two seasons, i forget the brand, but it's the one in the plastic tube with multiple reflector levels incased in the tube, attached high to the shrowds.

On multiple occasions, in fog, I’ve been contacted by commercial vessels. They’ve hailed me with a general description of my vessel i.e. “…white hulled sailing vessel, approximate length…” They’re seeking to obtain my intentions, and we arrange for a safe passing. These vessels are sometimes 7 nm away, my Raymarine E-80 doesn’t have the capability to “read” the vessel type. How do these commercial radar do it (remember we’re in fog and I made no previous radio contact to identify myself)?

[GBurton]

Night glasses? (Infrared)

[sailingdog]

IIRC, with a little modification, it should be able to be used on rod rigging.

Originally Posted by dave6330

OK - I have rod rigging on CIRRUS - will the Deluxe Echomaster's mounting hardware allow for easy installation on the shrouds rods? Starboard or Port (or does it matter)?

V/R

Dave

[sailaway21]

petegingrass,
It's quite likely that the merchant ships picked you up on their radar and had the advantage of being able to look for you with exact bearing and range. It's also possible that their vision was better than your's due to their height above the water. It's easier to catch a glimpse of a sailboat from 75' above the water than it is a ship from 5' above the water. An experienced radar operator may well know you're a sailboat as well from the painting of his radar screen. Sailboats show up with about the same return as a submarine periscope. Both can be chimerical.