RichH wrote in message ...
Ive often wondered for those situations where the approaching vessel has
lost your boat's radar image in the sea state clutter and you have the
god awful intuition that they CANT see you ... that a flare shell filled
with the appropriate aluminum 'chaff' and sent skywards would be in
order. Just imagine being on the bridge of freighter when suddenly what
appears on the radar screen in front of you is the size of an aircraft
carrier... and to be repeated several times. THAT would certainly get
someone's attention. Even if the bridge were unattended, such an 'event'
would most certainly set off a few automatic alarms .... if indeed the
radar scope was even on on that bridge.
Just an exercise in 'mental masturbation' but perhaps relevant to this
discussion.

Perhaps a cheapa/simple radar emitting device that would give such a
false image could be another possibility.

Such a device already exists. A few years back, I asked Pains-Wessex
if such a device wouldn't help in SAR operations and their reply was
that they manufactured the equoivalent of a parachute flar, but woith
chaff. The only propblem was that, duue to its costs, the only market
was the military...
OTOH, before I left for a transatlantic cruise, I fastened a second
radar reflector ( s mall 9" HYE model) close to the masthead on the
starboard side of the mast whilst I had the DAvis "Echomnaster"
hanging from the starbord spreader. All the shiops I spoke to on VHF
said they had seem me at "beetter than 10 miles distance" and the
captain of a Hapag-Lloyd container ship with whom I had quite a chat
(he must have had a Philipino crew to be so happy to encounter
somedody who understood German...) told me "You have a very good echo,
not a ship's echo, mind you, but a very good one for such a small
boat.." When I returned from Europe, I had taken off the masthead
reflector that had been damaged, and the reports said that I was only
seen at around 6 miles. It gave me confidence that even if my radar
went on the blink, I still had a chance to be seen, IF somebody was
looking at the screen...
john

bject: Vessel detectors - radar visibility of your own vessel
From: "Jack Rye"
Date: 08/24/2003 07:22 Pacific Standard Time
Message-id: cS32b.52869$kP.35422@fed1read03

Just a thought. The persons is concerned with battery drain. Buy Two pairs
of binoculars 20x60 for day and bright night. Buy night vision 5x
magnification with an illuminator. For those pitch black nights. Junk all
other electronics and pray that a cargo or cruise ship doesn't run you down

Jack

"RichH" wrote in message
...
Ive often wondered for those situations where the approaching vessel has
lost your boat's radar image in the sea state clutter and you have the
god awful intuition that they CANT see you ... that a flare shell filled
with the appropriate aluminum 'chaff' and sent skywards would be in
order. Just imagine being on the bridge of freighter when suddenly what
appears on the radar screen in front of you is the size of an aircraft
carrier... and to be repeated several times. THAT would certainly get
someone's attention. Even if the bridge were unattended, such an 'event'
would most certainly set off a few automatic alarms .... if indeed the
radar scope was even on on that bridge.
Just an exercise in 'mental masturbation' but perhaps relevant to this
discussion.

Perhaps a cheapa/simple radar emitting device that would give such a
false image could be another possibility.



SG If these ships are so big and easily seen and well lit and a small boat is
maintaining a good helmwatch and obeying the rules ..... how does one get
themselves soo close to one that they get "run down" by the ship ...... kinda
like "I was driving down the road and this 80 story skyscraper reared up and
hit me!!"

If you are maintaining a good watch, you should see him LONG before he sees
you.
At sea, never approach a ship closer than 2 mi. if you have the room.

Shen44 wrote:

SG If these ships are so big and easily seen and well lit and a
small boat is maintaining a good helmwatch and obeying the rules
..... how does one get themselves soo close to one that they get
"run down" by the ship ...... kinda like "I was driving down the
road and this 80 story skyscraper reared up and hit me!!"

With respect, your question makes me wonder exactly how many nights you have
spent well offshore in a small cruising sailboat. Things sometimes just
happen.

If you are maintaining a good watch, you should see him LONG before
he sees you. At sea, never approach a ship closer than 2 mi. if you have
the room.

Splendid advice. See above.

--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://kerrydeare.tripod.com

"Jack Rye" wrote
two pairs of binoculars 20x60 . . . night vision 5x
magnification with an illuminator

Although two pairs is a good idea (breakage), 20x magnification would
be useless on a boat. A pair of lightweight 8x25s for daylight bouy
reading, guests, etc., and a pair of good 7x50s for dawn dusk action.
They're not gonna work when it's dark, though.

No need for magnification on the NV device; it's a shape detection
tool. And the illuminator also isn't needed when boating, in that a
"million candlepower" searchlight serves better. NV is for loom
detection, shoreline observation, etc., distant viewing applications.

Neither does what radar does: penetrate fog, snow and rain. But then
radar requires a trained (according to the Coast Guard) operator on
station and good reflectance on the observed vessel, a step away from
directly "looking" at something using binos or NV. Surely doing your
part by hoisting a good reflector (inexpensive too) is proper
seamanship.

Subject: Vessel detectors - radar visibility of your own vessel
From: "Armond Perretta"
Date: 08/24/2003 11:36 Pacific Standard Time
Message-id:

Shen44 wrote:

SG If these ships are so big and easily seen and well lit and a
small boat is maintaining a good helmwatch and obeying the rules
..... how does one get themselves soo close to one that they get
"run down" by the ship ...... kinda like "I was driving down the
road and this 80 story skyscraper reared up and hit me!!"

With respect, your question makes me wonder exactly how many nights you have
spent well offshore in a small cruising sailboat. Things sometimes just
happen.

G Those nights existed in my past around N.E., but what has happened more, in
many areas was seeing a close aboard, dimly lit cruising sailboats, sometimes
at a point where my options are limited, and wondering how HE could let himself
get so close.
You're right, in that sometimes "chit" happens, and it happens on both sides of
this coin ..... just DON'T expect a ship to see you and/or react to you as you
might expect or want him to, or G you may hit that ship, and he won't have a
clue that you did.
Again .... never approach closer than two miles at sea, and if you miss the
ship and it's close aboard or within that distance, figure it's up to you to
avoid .... worry about some rule later.

If you are maintaining a good watch, you should see him LONG before
he sees you. At sea, never approach a ship closer than 2 mi. if you have
the room.

Splendid advice. See above.

--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://kerrydeare.tripod.com

Subject: Vessel detectors - radar visibility of your own vessel
From: "Armond Perretta"
Date: 08/24/2003 14:04 Pacific Standard Time
Message-id:

Shen44 wrote:

Again .... never approach closer than two miles at sea, and if you
miss the ship and it's close aboard or within that distance, figure
it's up to you to avoid .... worry about some rule later.

Always a sound approach, but consider this. I have a 4 to 4.5 knot
sailboat. Offshore the commercial traffic I encounter (neglecting for the
moment commercial fishermen) typically maintains 16 to 24 knots. Even
should I pick up a target at 8 miles on radar (or otherwise), there is in a
practical sense very little I can do to _insure_ a CPA of 2 miles or better.
I am speaking only from the perspective of quite a bit of offshore
cruising in a small sailing boat, which is not to say I don't realize that
"big boat always wins."


Oh, fiddle faddle. To begin with, not all ships you see out there will be
heading directly at you, so, for the most part, even at 4k, you will have
plenty of time to adjust.
Secondly, on a clear day you should be able to see a ship at 8mi plus and have
a good idea as to it's heading, which means you can take appropriate action to
give it as wide a berth as possible. Hey, if you don't make 2 mi., you
tried..... at least you worked to maximize the passing distance.
From my own standpoint, the "small" boat has a better chance of seeing the"big"
ship sooner (especially at night) and starting to maneuver to maximize the
passing distance .... especially, considering your slower rate of speed.
Don't get me wrong, I don't condone poor watch keeping on ships (visual and
radar) any more than I do so for small boats, but varied experience has taught
me that both have things which must be dealt with/ worked around, when dealing
with the other, and overall, small boaters should always act as if they are not
seen and maneuver accordingly ..... use the radio, shine a bright light on
your sails, use a strobe (short periods) .... do what it takes, never assume.

Shen

Single-handed - and asleep?

Brian W

On 24 Aug 2003 17:40:35 GMT, (Shen44) wrote:

SG If these ships are so big and easily seen and well lit and a small boat is
maintaining a good helmwatch and obeying the rules ..... how does one get
themselves soo close to one that they get "run down" by the ship ////

x-no-archive:yes
(Shen44) wrote:

Subject: Vessel detectors - radar visibility of your own vessel
From: "Armond Perretta"
Date: 08/24/2003 14:04 Pacific Standard Time
Message-id:

Shen44 wrote:

Again .... never approach closer than two miles at sea, and if you
miss the ship and it's close aboard or within that distance, figure
it's up to you to avoid .... worry about some rule later.

Always a sound approach, but consider this. I have a 4 to 4.5 knot
sailboat. Offshore the commercial traffic I encounter (neglecting for the
moment commercial fishermen) typically maintains 16 to 24 knots. Even
should I pick up a target at 8 miles on radar (or otherwise), there is in a
practical sense very little I can do to _insure_ a CPA of 2 miles or better.
I am speaking only from the perspective of quite a bit of offshore
cruising in a small sailing boat, which is not to say I don't realize that
"big boat always wins."


Oh, fiddle faddle. To begin with, not all ships you see out there will be
heading directly at you, so, for the most part, even at 4k, you will have
plenty of time to adjust.
Secondly, on a clear day you should be able to see a ship at 8mi plus and have
a good idea as to it's heading, which means you can take appropriate action to
give it as wide a berth as possible. Hey, if you don't make 2 mi., you
tried..... at least you worked to maximize the passing distance.

There are some boats, particularly off the FL coast which do not have
a heading that is stable. They are well lit so we can see them
(better than the little fishing boats which may be anchored at random
with no lights at all), but they don't maintain any kind of heading.
We used to think they got their kicks by heading for any small boat
they saw.

Actually I think they are gambling ships out just beyond the requisite
mile limit and aren't going anywhere particular. Bob's method of
dealing is to head for them at which point they seem to veer off.
We'd never catch them so that's probably safe.

From my own standpoint, the "small" boat has a better chance of seeing the"big"
ship sooner (especially at night) and starting to maneuver to maximize the
passing distance .... especially, considering your slower rate of speed.
Don't get me wrong, I don't condone poor watch keeping on ships (visual and
radar) any more than I do so for small boats, but varied experience has taught
me that both have things which must be dealt with/ worked around, when dealing
with the other, and overall, small boaters should always act as if they are not
seen and maneuver accordingly ..... use the radio, shine a bright light on
your sails, use a strobe (short periods) .... do what it takes, never assume.

How long does it take a large ship going at the rate of speed that
they normally go at to get from a blip on the horizon to the observer?
(8 miles? 12 miles?) If the ship is going 24 knots 8 nm would take
20 minutes. The small boat going 6 knots will take an hour and 20
minutes to do the same distance if I'm correct (and math isn't really
my thing) and will be able to separate from the larger ship's course
(if accurately determined) by two miles in that length of time..

You'd think that would be enough time to get out of the way, but that
assumes you can accurately tell at that distance what their course is,
that you are correct in the action that you take, that they maintain
the course and also that you see them 8 nm away by whatever means. If
you don't see them until they are 4 nm away, they will be at your boat
in 10 minutes, and in that length of time you can only get a mile.

There was a case here in the bay where a cruising boat running up the
western shore at night saw a ship on his radar and saw something else
that he couldn't ID, and apparently went down into the cabin to look
at a chart or get a cup of coffee or something, and he ran between a
tug and the tow and his boat sank within a couple of minutes.

So it isn't as clear-cut a problem as wanting each ship to keep proper
lookout IMHO


grandma Rosalie

S/V RosalieAnn, Leonardtown, MD
CSY 44 WO #156
http://home.mindspring.com/~gmbeasley/id2.html

Subject: Vessel detectors - radar visibility of your own vessel
From: Brian Whatcott
Date: 08/24/2003 18:07 Pacific Standard Time
Message-id:

Single-handed - and asleep?

Brian W


Yes .... well, that's a chance you take when doing this, and a whole nuther
argument.

Subject: Vessel detectors - radar visibility of your own vessel
From: Rosalie B.

There are some boats, particularly off the FL coast which do not have
a heading that is stable. They are well lit so we can see them
(better than the little fishing boats which may be anchored at random
with no lights at all), but they don't maintain any kind of heading.
We used to think they got their kicks by heading for any small boat
they saw.

Actually I think they are gambling ships out just beyond the requisite
mile limit and aren't going anywhere particular. Bob's method of
dealing is to head for them at which point they seem to veer off.
We'd never catch them so that's probably safe.

The one advantage to these types of ships, is they are normally well lit.
Problem is in seeing their running lights and narrowing down their heading at
night (and except for dead ahead, I wouldn't give you much chance of being
visually seen by them).
Hard to give good advice on these .... fraid you will have to take each case as
it comes, but still figure you are your own best solution.


How long does it take a large ship going at the rate of speed that
they normally go at to get from a blip on the horizon to the observer?
(8 miles? 12 miles?) If the ship is going 24 knots 8 nm would take
20 minutes. The small boat going 6 knots will take an hour and 20
minutes to do the same distance if I'm correct (and math isn't really
my thing) and will be able to separate from the larger ship's course
(if accurately determined) by two miles in that length of time..

You'd think that would be enough time to get out of the way, but that
assumes you can accurately tell at that distance what their course is,
that you are correct in the action that you take, that they maintain
the course and also that you see them 8 nm away by whatever means. If
you don't see them until they are 4 nm away, they will be at your boat
in 10 minutes, and in that length of time you can only get a mile.

The 2mi, is a number to strive for .... it's NOT written in stone.
Also, once again .... how many ships that you meet are heading directly at you?
That is only ONE case.
In many, if not most cases, they will be heading in a direction that crosses
your path, and here, it's important to figure out their "relative motion".
BTW, if you don't see a ship until it's 4 mi from you, on a relatively clear
day, you're not keeping a very good watch.
Normally, from the moment you spot the ship, it should take no more than one to
two minutes to get a good feel for the ship's basic heading and whether the
bearing is steady, opening, or closing .... at which point, your work begins.
Naturally,if you've got radar, this is easier, but if not, you need to do some
"eyeball" calculations, and these need to be watched closely to see if you are
getting the results you wish (probably means a greater course change than if
you had radar)

There was a case here in the bay where a cruising boat running up the
western shore at night saw a ship on his radar and saw something else
that he couldn't ID, and apparently went down into the cabin to look
at a chart or get a cup of coffee or something, and he ran between a
tug and the tow and his boat sank within a couple of minutes.

Two errors here (well a bunch, actually).
A tug and tow, is normally an easy radar spot (kinda like a triangle small
target leading a larger one, close together, maintaining a same distance
separation) so poor radar interpretation on his part..... and never leave the
radar, till you KNOW what you are seeing and what it's doing.

So it isn't as clear-cut a problem as wanting each ship to keep proper
lookout IMHO

It's a clear cut problem with BOTH vessels keeping a proper lookout, but not
clearcut as how you should respond for varying conditions .... I'm saying try
to stay at least 2 mi. clear. Well, we all know that's not always possible
.....it's a goal and one which can be attained, frequently, only by very early,
substantial action.

Shen