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Old 01-24-2011, 05:47 PM   #1
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Radar/Lightning

Inquiry*** Does the average size trawler, say between 35'and 50', with an average fly bridge or PH height, provide an adequate radar target or do you use a radar reflector located up higher?**** KJ

-- Edited by KJ on Monday 24th of January 2011 06:48:39 PM

-- Edited by KJ on Tuesday 25th of January 2011 09:09:59 AM
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Old 01-24-2011, 06:17 PM   #2
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RE: Radar

I've always heard that radar sees the biggest hunk of metal on your boat...your engine(s). That is, unless you're a metal boat.
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Old 01-24-2011, 06:20 PM   #3
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RE: Radar

We have a radar reflector but we've noticed that we sometimes get good returns from boats that don''t have one. It all depends on the mass of the boat, what kind of radar reflective surfaces are on or in it, how the boat is oriented relative to our boat, and how our radar is tuned.

When it's foggy we run in the fog, but when we do one person (usually my wife) drives and navigates using the GPS plotters and compass, and the other person (usually me) works the radar on an almost full-time basis. In order to make sure we don't miss something we are constantly adjusting the radar following radar operation procedures we've learned from a couple of books, one of them being a Royal Navy "how to use radar at sea" book. Strong and weak gains both show you things and overlook things. So the trick to seeing everything, from commercial crab pot buoys to Washington State ferries is to keep varying the display unit's adjustments.

We've gotten weak signals from boats that when we saw them proved to have a radar reflector installed and strong signals from boats that had no reflector, like the smaller sport fishing boats that are very numerous up here.

I think a radar reflector is very definitely worth having but I would not assume that just because you have one you will show up as a big, obvious target on everyone else's radar display all the time.* Lots of variables at work here, and some of them are in the hands of the operators of the boats around you.
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Old 01-24-2011, 06:34 PM   #4
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RE: Radar

I have one of the common metal Davis round shape reflectors strapped just the spreader of the mast. No idea if it helps, it can't hurt unless they are a lightning attractor. That reminds me there is a last years wasp nest up inone of the corners I need ot take out. i have thought about asking a tow how my reflection appears on his screen, haven't done it yet maybe next cruise. One of the boating magazines did a comprehensive study comparing different passive reflectors a couple of years ago sorry, I can't remember which maybe a google search will bring it up.
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Old 01-24-2011, 07:09 PM   #5
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RE: Radar

KJ,

We have a reflector on our boat.* I've asked boats around us how we show on their radar.* Most say we are clearly visible.* I have*no way of knowing whether it's the reflector or our boat (our bridge height is about 14 feet and we have twin engines and a generator) or both.* I wouldn't take it down to find out!* Like Marin said, we can't control how other boaters use and maintain their radar equipment and their ability to know what they "see", or "don't see".

I've attached a photo of the reflector (the "drum" shaped cylinder just below the anchor light on top of the mast).* I like the idea that it's high up on the mast.* The top of the mast is 22' 6" so the reflector is about 21 to 22 feet above the water.
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Old 01-24-2011, 08:13 PM   #6
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RE: Radar

WESTERLY has a Davis Echomaster mast-mounted in the catch-rain position.* Prior to permanent*install, we*went outside the marina and asked other mariners to look at our radar return with the unit up and down.* Even with our un-scientific test, it was clear that it aids in providing a good radar target, except when the mast blocks the radar signal from the reflector.

If the unit cannot be installed with a 360 exposure, a second unit*mounted in*the*weak/hidden*vector*may be helpful.
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Old 01-24-2011, 11:48 PM   #7
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RE: Radar

Quote:
Steve wrote:

I have one of the common metal Davis round shape reflectors strapped just the spreader of the mast. No idea if it helps, it can't hurt unless they are a lightning attractor.** Steve
I think I can hijack my own thread.
I've been meaning to ask, has anyone, particularly in the tropics, ever had their boat hit by lightning. I vaguely remember something about sailboats running a copper (?) strip down mast to the bottom of the hull as a ground, so that if hit, it wouldn't fry all the electronics.* I would imagine with a lower profile, trawlers wouldn't be at the same risk as a sailboat. So again, has anyone been hit or heard of a trawler being hit?*** KJ**

*
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Old 01-24-2011, 11:55 PM   #8
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RE: Radar

Haven't had it happen or seen it happen but at least one person on the GB forum has had it happen. It hit the mast and toasted all the boat's electronics.
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Old 01-25-2011, 08:13 AM   #9
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RE: Radar/Lightning

I am curious if areas that are more prone to lightning strikes like east coast (Fla, NC), have any incidents of boats getting hit.* KJ
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Old 01-25-2011, 08:25 AM   #10
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RE: Radar/Lightning

Last Summer a guy in my Marina was offshore in his 40' Viking with a tower.* His boat got struck- 30k damage to electronics.* That day his fishing buddies included a Roman*
Catholic Priest.** Makes one think.*
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Old 01-25-2011, 12:14 PM   #11
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RE: Radar/Lightning

Quote:
Mike wrote:

Quote:
I am curious if areas that are more prone to lightning strikes like east coast (Fla, NC), have any incidents of boats getting hit.* KJ
Sure. Several boats a year get struck here in central FLA.

There is sailboat on my dock that has been struck twice in the last 4 years.

The first time it was struck my DeFever was in the slip next to it.

I reported the strike on the boat next to me to my insurance carrier and they sent a surveyor out and paid to haul my boat to inspect for damage.

We could not find any evidence of a strike on my boat, but every electronic device was kaput - instruments, chart plotters, radios, battery chargers, transducers, alternators, etc.



Mike
Merritt Island, FL.
Did you have to replace the boats wiring?*
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Old 01-25-2011, 04:19 PM   #12
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RE: Radar/Lightning

Quote:
JohnP wrote:

Last Summer a guy in my Marina was offshore in his 40' Viking with a tower.* His boat got struck- 30k damage to electronics.* That day his fishing buddies included a Roman*
Catholic Priest.** Makes one think.*
Now, that is really thinking.* I had never thought of having a Chaplain on board.* Makes sense!

*
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Old 01-25-2011, 04:43 PM   #13
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RE: Radar/Lightning

Quote:
Moonstruck wrote:


JohnP wrote:

Last Summer a guy in my Marina was offshore in his 40' Viking with a tower.* His boat got struck- 30k damage to electronics.* That day his fishing buddies included a Roman*
Catholic Priest.** Makes one think.*
Now, that is really thinking.* I had never thought of having a Chaplain on board.* Makes sense!

*

Was anyone injured?* Any other damage to the boat?

*
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Old 01-25-2011, 05:24 PM   #14
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RE: Radar/Lightning

Clergy on boats/ships is a no no. As bad as women aboard. Bad ju ju. My father, an (Anglo) Catholic priest, told of boarding a steamer in the 1930's in his clerical duds and having the crew spot him, roll their eyes and cross themselves. Sure enough, it was a rough trip weather wise.
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Old 01-25-2011, 06:20 PM   #15
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RE: Radar/Lightning

Glad I don't boat in Florida with its surplus of lightning. ... Perhaps a Marina with tall hills/mountains/buildings around has something in its advantage.
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Old 01-26-2011, 06:32 AM   #16
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RE: Radar/Lightning

The best radar antenna is still the biggest thing with precise 90 deg corners.

The surplus life raft folding units from WWII surplus are cheap and really effective.
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Old 01-26-2011, 06:54 AM   #17
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Radar/Lightning

There were no injuries on the Viking (Thank God)

The electronics were toasted, and a lot of the wiring on the tower was damaged.

Some work was done on the panel to replace breakers and gauges.

The weather was wet and only the Captain was on the bridge the rest of the crew were in the deck house.

The boat was returning to the inlet at approx 18knots.


-- Edited by JohnP on Wednesday 26th of January 2011 07:56:03 AM
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Old 01-26-2011, 10:06 AM   #18
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RE: Radar/Lightning

When I lived at A&B marina in Key West, a sport fisher came in after being hit by lightning, the bolt exited the dashboard on the upper helm and blew a huge hole. The Capt. was sitting there under way and he looked like he had been shot with a shotgun,fiberglass shrapnal. He survived with lots of scars. Last summer here in Belize, a dive boat headed out to the blue hole was hit at the upper helm and exited through a crewman on the lower deck, he did not live. We are the highest thing aroun when were on the sea , and make pretty good targets. BB
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Old 01-27-2011, 11:26 PM   #19
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RE: Radar/Lightning

Again, if you*do your boating*in a lightning prone area, is it possible to shield your electronics from damage if you get hit? Aren't aircraft instruments shielded?
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Old 01-28-2011, 06:21 AM   #20
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RE: Radar/Lightning

is it possible to shield your electronics from damage if

YES BUT , to do a proper job they would all need to be disconnected from power and antennas and probably kept in a Faraday Cage .
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