"Roger Long" wrote in
:

The numbers in the British study aside, what do those of us in midsize
fiberglass sailboats generally look like to you in the real world? Do
you often see a boat with a radar reflector hanging that didn't show
up on the scope? Are we little blips that you could easily overlook?
How would you rate the chances of a vessel over running its visibility
in fog not seeing a radar reflector equipped boat?


I have a friend who is a ham radio operator and ship master of a 950'
SeaLand container ship. I asked him a similar question, so we went up on
his bridge and fired off the ships radar at the dock in downtown
Charleston, right in the harbor. It was Saturday and there were LOTS of
small boats/sailboats to target.....

The big radar antenna is, of course, way up on the mainmast probably
180' off the water, to the detriment of all the 50' radar reflectors it
shoots completely OVER within about a mile of the ship. The radar
antennas don't point down to avoid sea clutter mucking up the screens.
So, the radiated beam is restricted by a plate under it to limit downward
radiation. Once you're in the shadow of that plate, nothing will make
you "seen" by the radar operator....when it counts the most.

From the downtown dock on the seaward side of the Cooper River bridges,
the first detectable targets I could see were about even with Ft Sumter
on the OTHER side of the harbor. I used a really nice pair of stabilized
binoculars to visually spot what I could see on the screen and the
nearest target was a big sloop showing a radar reflector hanging under
his spreaders. The other targets moving around were past Ft Sumter out
in the ship channel. Even then, most of the sailboats never made a dot
on the screen with no reflector. The steel ships all made quite a blob,
even way out to our horizon. Some of the shrimp boats had a return
shrimping offshore.

Most of the plastic bubbleboats, even those 60' monsters barely showed up
unless they had a reflector, either.

This is all with the ship sitting perfectly upright and having a clear
view of the horizon on a clear day. From the bridge, I could see quite a
ways at sea out past the Jetties and offshore to the South over Noname
Island by Ft Sumter. I'm sure if your radar reflector were at 50' in 6'
seas, or worse, and the monster ship were rolling, you'd make even less
of an impressive blob than I saw.

If you ever get a chance to try it for yourselves, do light it off and
test your own theories. I sure wouldn't depend on the radar op seeing my
40' plastic boat at all, radar reflector or not. I think it's wishful
thinking and a LOT of luck.

Cap'n Larry told me to tell all my sailor friends that NOONE on his ship
is bothered, at all, if you CALL THEM ON CHANNEL 13 OR 16 TO LET THEM
KNOW YOU ARE THERE! I've always gotten a thank you from their bridge
after asking them if they see us crossing their path. Some did...many
didn't! Why sailors are so goddamned TIMID to talk to ships on the radio
has always been a mystery to me. Those guys on the bridge are BORED TO
TEARS! They're not busy, at all, as the ship drives itself. Especially
on the midwatch, I've spent hours talking to whatever mate is driving on
Channel 13 out beyond land. There's just you and him and you're not
jamming the dead channel at all.

I declined one mate's offer to swap Geoffrey's Endeavour 35 for a 450'
freighter full of bananas and fuel....(c; Both our captains were
asleep...hee hee. How many bananas can YOU eat?...(c; You'll find them
ALL very curious to know all about your boats. They've never been
sailing.







These *******s keep calling me so I'm feeding them to the spambots.
--
Sunrise Communications
1374 E. Republic Rd.
Springfield, MO 65804
866-483-1228
417-886-7091
http://www.sunrisecommunicationsinc.com/
877-842-3210
866-842-3278
United Healthcare
http://www.unitedhealthcareonline.com/

Larry wrote:

If you ever get a chance to try it for yourselves, do light it off and
test your own theories. I sure wouldn't depend on the radar op seeing my
40' plastic boat at all, radar reflector or not. I think it's wishful
thinking and a LOT of luck.

Aww crap Larry...now all I gotta do is find a genuine Homeland Security
approved active ECM critter and I'm good. Wonder how the Coasties and
Skimmers will feel about this...

In article ,
Larry wrote:

The big radar antenna is, of course, way up on the mainmast probably
180' off the water, to the detriment of all the 50' radar reflectors it
shoots completely OVER within about a mile of the ship. The radar
antennas don't point down to avoid sea clutter mucking up the screens.
So, the radiated beam is restricted by a plate under it to limit downward
radiation. Once you're in the shadow of that plate, nothing will make
you "seen" by the radar operator....when it counts the most.

Ahhh, Larry but you didn't gives us the most important piece of
information abut this "BIG" radar. Was it X-Band or S-Band?????
That will make a HUGH difference, in what Targets it paints, at
what distance....

ALL these 1500 Gross Ton or larger carry both......

Bruce in alaska
--
add a 2 before @

Bruce in Alaska wrote in news:bruceg-
:

Ahhh, Larry but you didn't gives us the most important piece of
information abut this "BIG" radar. Was it X-Band or S-Band?????
That will make a HUGH difference, in what Targets it paints, at
what distance....

ALL these 1500 Gross Ton or larger carry both......



Hmm...sorry. Standing at the odd-looking console watching targets with
Cap'n Larry I never asked. I never saw the transmitter, sorry.

I suppose my point is plastic boat sailors THINK the big guys can spot
them, on radar and visually. I suppose they COULD if we move the bridge
to the bow or take off all the containers in the way, but that isn't
gonna happen. The flag is 930' in front of the helm. You all know what
the genoa does to your ability to see those damned crabpot toilet floats
from your helm. Imagine if the obstruction were 900' FORWARD of your
bow! They can't really see anything less than a full sized ship, on
radar or out the windows. There are hardly any sailors aboard these huge
ships run by computers. The crews are, to increase profits, tiny in
respect to the size of the beast. There aren't 15 people with binoculars
standing on the bow, in a crow's nest looking out for icebergs and
Catalinas, guys standing on the bridge wings scanning the horizon for 4
hours like a Navy ship has. There's one guy, walking around the bridge,
bored to tears as the computer watches the GPS and flogs on towards
Holland....just like last week, last month, last year...
(yawn).....zzzzzZZZZ.





These *******s keep calling me so I'm feeding them to the spambots.
--
Sunrise Communications
1374 E. Republic Rd.
Springfield, MO 65804
866-483-1228
417-886-7091
http://www.sunrisecommunicationsinc.com/
877-842-3210
866-842-3278
United Healthcare
http://www.unitedhealthcareonline.com/

Larry wrote:

I suppose my point is plastic boat sailors THINK the big guys can spot
them, on radar and visually. I suppose they COULD if we move the bridge
to the bow or take off all the containers in the way, but that isn't
gonna happen. The flag is 930' in front of the helm. You all know what
the genoa does to your ability to see those damned crabpot toilet floats
from your helm. Imagine if the obstruction were 900' FORWARD of your
bow! They can't really see anything less than a full sized ship, on
radar or out the windows. There are hardly any sailors aboard these huge
ships run by computers. The crews are, to increase profits, tiny in
respect to the size of the beast. There aren't 15 people with binoculars
standing on the bow, in a crow's nest looking out for icebergs and
Catalinas, guys standing on the bridge wings scanning the horizon for 4
hours like a Navy ship has. There's one guy, walking around the bridge,
bored to tears as the computer watches the GPS and flogs on towards
Holland....just like last week, last month, last year...
(yawn).....zzzzzZZZZ.

I think (from memory) the IMO rules require you to see only 2 boat
lengths from the BOW. So visibility can be impaired say anywhere
within 1800' of the bow...

I ALWAYS assume I am invisible to big ships and steer accordingly. On
offshore passages I've called passing ships and ask if they can see me
on radar. Often the reply is "let me get it warmed up"...

Evan Gatehouse

On Aug 14, 5:25 pm, Evan Gatehouse
wrote:
....
I think (from memory) the IMO rules require you to see only 2 boat
lengths from the BOW. So visibility can be impaired say anywhere
within 1800' of the bow...
....

I haven't read the IMO treaties and case law but the way it was taught
to me was that a lookout had to be as far forward and low as
practicable (preferably but not necessarily off the bridge). Five, as
written, clearly doesn't allow 1800' blind spots, but maybe the courts
do. However, I don't mean to quibble. You are absolutely right to
assume that you are invisible to all targets that pose a risk of
collision unless you have had positive communication with them and
come to a passing agreement.

-- Tom.

Evan Gatehouse wrote in news:Bmuwi.58787
$_d2.38488@pd7urf3no:

I've called passing ships and ask if they can see me
on radar. Often the reply is "let me get it warmed up"...



I think that's a more common response than we'd like to think about.

They just don't care or have the time to care....which makes no difference
as you go under the bulb.

Sailors offshore need to take a more intense interest in calling them to
KEEP THE WATCH AWAKE, out of his stupor, especially on the midwatch.