Useful gadgets
 

On 28 Jan 2004 07:07:38 -0800, (Parallax)
wrote:

Jack Dale wrote in message . ..
On 24 Jan 2004 09:18:25 -0800, (Parallax)
wrote:


Any other useful things?

Portland Plotter - after one of my coastal navigation students showed
me one I put away the parallel rules. I still like a Douglas
protractor, but I use the parallel rules as an antique. The Plotter
is my mainstay.

After I demonstrate all 3, almost all of my students opt for the
Portland Plotter.

Jack


Portland Plotter? I'll do a search on it.

I hate the parallel rules because they are hard to use with the chart
spread on a pitching cabin floor. Instead I use my hand bearing
compass mounted to aplastic square I can align with north and
perpendicular to the edge of the chart. I have a protractor mounted
to it so I can rotate it about the compass axis. Works for me.
Around here, in most cases, i can ignore the difference between
magnetic north and true north.


The Portland Plotter has a scale that permits instant conversion for
variation. We have 19 degrees east in the Gulf Islands.

The manufacturer's web site is:

http://www.blundellharling.co.uk/nav...ucts/index.asp

Jack

__________________________________________________
Jack Dale
Swiftsure Sailing Academy
Director/ISPA and CYA Instructor
http://www.swiftsuresailing.com
Phone: 1 (877) 470-SAIL (toll free)
__________________________________________________

Useful gadgets
 

Steven Shelikoff wrote:
On 28 Jan 2004 02:05:18 GMT, (JAXAshby) wrote:


then how come you are such a dumb squat when it comes to radar?


I probably spend more time as
radar observer, on my week off, than you do in a year.

indeed, you didn't even know you need nearly flat water to see low rocks with
radar, as witness your statement below:


That may have been true in the 40's and 50's. It's not true anymore.
There are all sorts of techniques modern radars use to find things like
low rocks in sea clutter, from simple ones like scan averaging and
doppler filtering to complex adaptive filters which model the sea
clutter and remove it.

Steve

All true, but I was referring to the standard everyday radar which most
boaters will be using.
Although "sea return" normally is a pain in the butt, it can be useful.
For instance, it can be used to pick up a reef line; in the case above,
it will accent the rock which may be just below or just above the
surface; I've used it to identify a particular boat which throws a nasty
wake that can be seen on radar.
All of the above are not guaranteed and depend on conditions, but when
the conditions are right they can be useful tools.

otn

Useful gadgets
 

Steven Shelikoff wrote:
On 28 Jan 2004 02:05:18 GMT, (JAXAshby) wrote:


then how come you are such a dumb squat when it comes to radar?


I probably spend more time as
radar observer, on my week off, than you do in a year.

indeed, you didn't even know you need nearly flat water to see low rocks with
radar, as witness your statement below:


That may have been true in the 40's and 50's. It's not true anymore.
There are all sorts of techniques modern radars use to find things like
low rocks in sea clutter, from simple ones like scan averaging and
doppler filtering to complex adaptive filters which model the sea
clutter and remove it.

Steve

All true, but I was referring to the standard everyday radar which most
boaters will be using.
Although "sea return" normally is a pain in the butt, it can be useful.
For instance, it can be used to pick up a reef line; in the case above,
it will accent the rock which may be just below or just above the
surface; I've used it to identify a particular boat which throws a nasty
wake that can be seen on radar.
All of the above are not guaranteed and depend on conditions, but when
the conditions are right they can be useful tools.

otn

Useful gadgets
 

bud-bud, you are talking about using radar in flat calm water, not water with
movement. In anything but flat calm water you can even see a fiberglass
sailboat, let alone a submerged reef or rock.

besides, why are you wandering around in unknown waters in a fog at speed?
dumb.

Steven Shelikoff wrote:
On 28 Jan 2004 02:05:18 GMT, (JAXAshby) wrote:


then how come you are such a dumb squat when it comes to radar?


I probably spend more time as
radar observer, on my week off, than you do in a year.

indeed, you didn't even know you need nearly flat water to see low rocks
with
radar, as witness your statement below:


That may have been true in the 40's and 50's. It's not true anymore.
There are all sorts of techniques modern radars use to find things like
low rocks in sea clutter, from simple ones like scan averaging and
doppler filtering to complex adaptive filters which model the sea
clutter and remove it.

Steve

All true, but I was referring to the standard everyday radar which most
boaters will be using.
Although "sea return" normally is a pain in the butt, it can be useful.
For instance, it can be used to pick up a reef line; in the case above,
it will accent the rock which may be just below or just above the
surface; I've used it to identify a particular boat which throws a nasty
wake that can be seen on radar.
All of the above are not guaranteed and depend on conditions, but when
the conditions are right they can be useful tools.

otn

Useful gadgets
 

bud-bud, you are talking about using radar in flat calm water, not water with
movement. In anything but flat calm water you can even see a fiberglass
sailboat, let alone a submerged reef or rock.

besides, why are you wandering around in unknown waters in a fog at speed?
dumb.

Steven Shelikoff wrote:
On 28 Jan 2004 02:05:18 GMT, (JAXAshby) wrote:


then how come you are such a dumb squat when it comes to radar?


I probably spend more time as
radar observer, on my week off, than you do in a year.

indeed, you didn't even know you need nearly flat water to see low rocks
with
radar, as witness your statement below:


That may have been true in the 40's and 50's. It's not true anymore.
There are all sorts of techniques modern radars use to find things like
low rocks in sea clutter, from simple ones like scan averaging and
doppler filtering to complex adaptive filters which model the sea
clutter and remove it.

Steve

All true, but I was referring to the standard everyday radar which most
boaters will be using.
Although "sea return" normally is a pain in the butt, it can be useful.
For instance, it can be used to pick up a reef line; in the case above,
it will accent the rock which may be just below or just above the
surface; I've used it to identify a particular boat which throws a nasty
wake that can be seen on radar.
All of the above are not guaranteed and depend on conditions, but when
the conditions are right they can be useful tools.

otn

Useful gadgets
 

Useful gadgets
 

Useful gadgets
 

Subject: Useful gadgets
From: (JAXAshby)
Date: 01/28/2004 09:50 Pacific Standard Time
Message-id:

bud-bud, you are talking about using radar in flat calm water, not water with
movement. In anything but flat calm water you can even see a fiberglass
sailboat, let alone a submerged reef or rock.

Jax, as others have said, you need to get back on your "meds".
He was NOT talking about flat calm conditions, alone. He was discussing calm as
well as conditions where a sea is running.
As he said, you don't have enough basic knowledge or experience to understand
any of this.


besides, why are you wandering around in unknown waters in a fog at speed?
dumb.

No one said anything about "at speed", but as to the rest, that's why one has
charts, GPS's, Radar, Fathometers, etc., coupled with the ability to use them.
Again, probably beyond your comprehension.

Shen

Useful gadgets
 

Subject: Useful gadgets
From: (JAXAshby)
Date: 01/28/2004 09:50 Pacific Standard Time
Message-id:

bud-bud, you are talking about using radar in flat calm water, not water with
movement. In anything but flat calm water you can even see a fiberglass
sailboat, let alone a submerged reef or rock.

Jax, as others have said, you need to get back on your "meds".
He was NOT talking about flat calm conditions, alone. He was discussing calm as
well as conditions where a sea is running.
As he said, you don't have enough basic knowledge or experience to understand
any of this.


besides, why are you wandering around in unknown waters in a fog at speed?
dumb.

No one said anything about "at speed", but as to the rest, that's why one has
charts, GPS's, Radar, Fathometers, etc., coupled with the ability to use them.
Again, probably beyond your comprehension.

Shen

Useful gadgets
 

hey shun, he only *thinks* he is talking about water with seas, but he is not.
He is, in fact, talking about flat water. That he is ignorant of that fact in
no way changes that fact.

go back to sleep, shun.

bud-bud, you are talking about using radar in flat calm water, not water
with
movement. In anything but flat calm water you can even see a fiberglass
sailboat, let alone a submerged reef or rock.

Jax, as others have said, you need to get back on your "meds".
He was NOT talking about flat calm conditions, alone. He was discussing calm
as
well as conditions where a sea is running.
As he said, you don't have enough basic knowledge or experience to understand
any of this.


besides, why are you wandering around in unknown waters in a fog at speed?
dumb.

No one said anything about "at speed", but as to the rest, that's why one has
charts, GPS's, Radar, Fathometers, etc., coupled with the ability to use
them.
Again, probably beyond your comprehension.

Shen