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Old 15-02-2013, 07:49   #76
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Re: Radar Reflector Review,to Have or Not to Have?

what a great thread this turnd out to be!
thanks to all who have posted ,pro and con alike,
though i'm firmly convinced having one is better than not
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Old 15-02-2013, 07:58   #77
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Re: Radar Reflector Review,to Have or Not to Have?

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Originally Posted by atoll View Post
what a great thread this turnd out to be!
thanks to all who have posted ,pro and con alike,
though i'm firmly convinced having one is better than not

I agree ,- good information and having one is best! I also think that it's apparent that the best reflector to be seen in offshore swells with sea clutter may be a different choice that what I and others find useful poking about protected coastal islands in the fog.
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Old 15-02-2013, 08:17   #78
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Re: Radar Reflector Review,to Have or Not to Have?

Wow, it is like religion. I've been told that my boat is extremely visible, in part I think because I have 3 outboards well above the water line; a boat with a fuel tank and engine in the bilge would be logically different.

This is the most readable study I found.
(http://www.seagrant.umaine.edu/files...al/05raref.pdf

This one is more laboratory.
http://offshore.ussailing.org/Assets...r+Test.pdf.pdf

I really like that the tin foil hat won (there were good reasons why--read the report).

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Old 15-02-2013, 08:27   #79
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Re: Radar Reflector Review,to Have or Not to Have?

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If shape and reflection wasn't 'everything' I wonder what they used as their base philosophy when designing stealth technology
Well said.

I won't waste brain cells getting involved in the theoretical part of this conversation other than to point out that all the stuff that MIGHT reflect, rather than scatter radar beams on your boat, other than the mast, is how high above the surface of the water? How many meters of freeboard do you have? This is going to do Sweet Fanny Apple for you if you are hull down in a seaway, lost in the swell, don't you think?

That just leaves your mast, and as others have said, if you are heeled, the surface of your mast looks a lot like the side of a stealth aircraft. I somehow doubt you're going to get a good radar reflection off that.

I have a great big fender-shaped passive radar reflector at about the level of my third spreaders, so probably 60 feet above the water. I know from talking to the bridges of different ships (I sail in the busiest shipping lanes in the world, so have plenty of opportunities to ask) that I am well visible from 10 miles off plus, heeled or not. I feel pretty sure that that's not the reflection from my davits or anchor rollers, they're seeing from 10 miles away, when they are still hull-down to me.

Of course if you are transmitting AIS the whole conversation is probably moot. I'm installing AIS as we speak, but I still don't think I'm going to take down my radar reflector. I couldn't do it, anyway -- radar reflectors are required for UK flagged vessels of any size.
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Old 15-02-2013, 08:46   #80
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Re: Radar Reflector Review,to Have or Not to Have?

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Originally Posted by thinwater View Post
Wow, it is like religion. I've been told that my boat is extremely visible, in part I think because I have 3 outboards well above the water line; a boat with a fuel tank and engine in the bilge would be logically different.

This is the most readable study I found.
(http://www.seagrant.umaine.edu/files...al/05raref.pdf

This one is more laboratory.
http://offshore.ussailing.org/Assets...r+Test.pdf.pdf

I really like that the tin foil hat won (there were good reasons why--read the report).

)
The kayak test really underlines the importance of height of whatever you expect to reflect radar beams.

The other test shows the spectacular performance of Sea Me active reflectors. It also shows that the better passive reflectors provide an average effective radar cross section of nearly a whole square meter (that's around ten square feet) even when heeled over at 20 degrees, and more than 10 square meters (that's 106 square feet) on an even keel. A square meter of effective radar cross section at 60 feet above the water, when heeled, sounds pretty good to me. I'm pretty sure my mast will be dead invisible by then, and the outboard on my dinghy in my davits will be lost in the sea clutter.
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