Depth sounder calibration
 

I wonder what would the best way to calibrate a depth sounder.
From what I read most depth sounders default setting are calibrated from
the transducer to the sea bed.
Other prefer to adjust the setting to the water line to the bottom of the
sea or from the bottom of the keel.
I wonder what is the preferred method of calibrating?

Depth sounder calibration
 

Depth sounder calibration
 

Lew Hodgett brought forth on stone tablets:
wrote:
I wonder what would the best way to calibrate a depth sounder.

The only thing that counts is how much water is under the keel.

Lew

Absolutely true Lew. And yet, I leave mine set to show the depth of
water between the transducer and the sea bed. This is a built in safety
margin which I really like to have. Keeps the occasional rock, stump,
etc on the bottom from having a close encounter with my keel. Or a deep
trough from a passing Bayliner from dropping me to the bottom.

bob
s/v Eolian
Seattle

Depth sounder calibration
 

"RW Salnick" wrote in message
...
Lew Hodgett brought forth on stone tablets:
wrote:
I wonder what would the best way to calibrate a depth sounder.

The only thing that counts is how much water is under the keel.

Lew

Absolutely true Lew. And yet, I leave mine set to show the depth of water
between the transducer and the sea bed. This is a built in safety margin
which I really like to have. Keeps the occasional rock, stump, etc on
the bottom from having a close encounter with my keel. Or a deep trough
from a passing Bayliner from dropping me to the bottom.

bob
s/v Eolian
Seattle

I agreed with the fact that what counts is how much water is under the keel
However, I have been, for years, using the depth to validate my position on
the chart.
Conversely, with today's electronics I could say 100 feet + 6 (draft) should
read 106 feet on the chart.
This way I could validate my position with the radar and GPS.

Depth sounder calibration
 

Depth sounder calibration
 

wrote in message
...
I wonder what would the best way to calibrate a depth sounder.
From what I read most depth sounders default setting are calibrated from
the transducer to the sea bed.
Other prefer to adjust the setting to the water line to the bottom of the
sea or from the bottom of the keel.
I wonder what is the preferred method of calibrating?

I have mine set at the bottom trailing edge of my outboard rudder, being
that is lowest point. That is the zero point and I have the alarm set for
three feet. I want to know the ground clearance rather than how deep the
water is at this point. This carries over from my flying days.
Leanne

Depth sounder calibration
 

On 2007-06-26 19:39:48 -0400, Lew Hodgett said:

wrote:

I agreed with the fact that what counts is how much water is under the keel

However, I have been, for years, using the depth to validate my
position on the chart. Conversely, with today's electronics I could say
100 feet + 6 (draft) should read 106 feet on the chart.

This way I could validate my position with the radar and GPS.

Trying to use chart data, some of it at least 100 years old, to
validate depth, to validate position?

You have got to be kidding.

If you find yourself in less than 20 ft of water, time for a lead line, IMHO.

At that point, screw the instruments.

Lew

Obviously, you don't sail the Chesapeake. We spend most of our time in
less than 20 feet; sometimes our speed reads greater than the depth. We
often raft up with others, so knowing the actual depth is even handier.

We originally calibrated by anchoring where we had a fairly flat
bottom, measured the depth, then adjusted the gauge to match. If it
reads 4.3, we're floating; 4.2 means we just bumped.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's new pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI pages: http://homepage.mac.com/jerelull/BVI/

Depth sounder calibration
 

Jere Lull wrote:

Obviously, you don't sail the Chesapeake. We spend most of our time in
less than 20 feet; sometimes our speed reads greater than the
depth. We
often raft up with others, so knowing the actual depth is even handier.

Actually, waters that are very similar to C/B, mostly the western 1/3
of Lake Erie; however, Detroit and St Clair Rivers as well as Lake St
Clair can make things very interesting on your way to Lake Huron.

You learn to stay at least a mile off shore, and then head straight in
when it is time to go to port.

The shore line is definitely not your friend.

If you don't touch bottom at least once over the weekend, , you stayed
in your slipG.

Lew

Depth sounder calibration
 

Lew Hodgett wrote:
however, Detroit and St Clair Rivers as well as Lake St Clair
can make things very interesting on your way to Lake Huron.

You learn to stay at least a mile off shore, and then head straight in
when it is time to go to port.

I learned to waterski and jump freighter wakes in the Detroit River. First time I fell I was shocked
to be able to stand in neck deep water 1000' from shore...you see in 1968, you couldn't see the bottom
in 5' of water in the Detroit River!!!

Depth sounder calibration
 

In article et,
Lew Hodgett wrote:

wrote:


I agreed with the fact that what counts is how much water is under
the keel
However, I have been, for years, using the depth to validate my
position on
the chart.
Conversely, with today's electronics I could say 100 feet + 6
(draft) should
read 106 feet on the chart.
This way I could validate my position with the radar and GPS.

Trying to use chart data, some of it at least 100 years old, to
validate depth, to validate position?

You have got to be kidding.


If you find yourself in less than 20 ft of water, time for a lead
line, IMHO.

At that point, screw the instruments.

Lew

I sail in a very shallow lake where walking on water is not a miracle.

Some people buy fish finders so they can see the rocks.

Have fun

Depth sounder calibration
 

In article ,
wrote:

I wonder what would the best way to calibrate a depth sounder.
From what I read most depth sounders default setting are calibrated from
the transducer to the sea bed.
Other prefer to adjust the setting to the water line to the bottom of the
sea or from the bottom of the keel.
I wonder what is the preferred method of calibrating?

My depth sounder is one foot bellow the water line. This gives me a good
reference to the water levels printed on the chart plus the proverbial
pilot foot.

Have fun

Depth sounder calibration
 

* wrote, On 6/26/2007 5:32 PM:
I wonder what would the best way to calibrate a depth sounder.
From what I read most depth sounders default setting are calibrated from
the transducer to the sea bed.
Other prefer to adjust the setting to the water line to the bottom of the
sea or from the bottom of the keel.
I wonder what is the preferred method of calibrating?


Do people still use regular sounders? Aren't fishfinders so much
better that everyone has gone to them?

Depth sounder calibration
 

On Jun 26, 7:39 pm, Lew Hodgett wrote:
wrote:

I agreed with the fact that what counts is how much water is under
the keel
However, I have been, for years, using the depth to validate my
position on
the chart.
Conversely, with today's electronics I could say 100 feet + 6
(draft) should
read 106 feet on the chart.
This way I could validate my position with the radar and GPS.

Trying to use chart data, some of it at least 100 years old, to
validate depth, to validate position?

You have got to be kidding.

If you find yourself in less than 20 ft of water, time for a lead
line, IMHO.

At that point, screw the instruments.

Lew

I agree with Lew, their's also tides and water level varriation due to
wind to contend with, not to mention if they have dredged since your
chart was updated. Using depth to tell where you are is really only
useful if your running out of water. If your chartplotter says their
should be 10 feet of water, and your depth sounder says their's only
2, you've got a problem. If you'r coming in from way offshore, depth
can tell you when you'r getting close to the beach, but that's it,
nothing more.

John

Depth sounder calibration
 

In article ,
stormtactic wrote:

In article et,
Lew Hodgett wrote:

wrote:


I agreed with the fact that what counts is how much water is under
the keel
However, I have been, for years, using the depth to validate my
position on
the chart.
Conversely, with today's electronics I could say 100 feet + 6
(draft) should
read 106 feet on the chart.
This way I could validate my position with the radar and GPS.

Trying to use chart data, some of it at least 100 years old, to
validate depth, to validate position?

You have got to be kidding.


If you find yourself in less than 20 ft of water, time for a lead
line, IMHO.

At that point, screw the instruments.

Lew

I sail in a very shallow lake where walking on water is not a miracle.

Some people buy fish finders so they can see the rocks.

Have fun

Up here, in alaska, we walk on water every winter! You just have to
wait for it to get "Stiff"......

Bruce in alaska I have pictures.......
--
add a 2 before @

Depth sounder calibration
 

... Using depth to tell where you are is really only
useful if your running out of water....

Given a working GPS and a WGS correctable chart that may be true.
Those of us who need to work our pilotage in places without GPS
correctable charts still find echo sounders useful tools for
navigation at times. These days this is kind of a specialized use
and as long as you know how the sounder was calibrated it is easy to
do any needed instrument corrections in your head. In the "old days"
when LORAN and RADAR were rare on small boats we used echo sounders
for navigation all the time even in pretty deep water.

-- Tom.

Depth sounder calibration
 

Over here we tend to use the depth sounder more for navigational purposes
and adjusting the scope when anchoring.
I do not think that a depth sounder is ideal for grounding avoidance. By
the time your shallow alarm is sounding you may be already aground. Local
knowledge and experience is probably the best for grounding avoidance.
Over here we have sea bed sedimentation movement. One day you may get
thought the gut and after a wind storm or freshet you may hit the bottom.
My new sailboat draws 6'-2". Today Bruce went thought the gut with his 4
foot draft boat and fed back his depth reading of 6'-6" at low tide via VHF.
Then I proceeded through the narrow passage and made it.


wrote in message
ps.com...
... Using depth to tell where you are is really only
useful if your running out of water....

Given a working GPS and a WGS correctable chart that may be true.
Those of us who need to work our pilotage in places without GPS
correctable charts still find echo sounders useful tools for
navigation at times. These days this is kind of a specialized use
and as long as you know how the sounder was calibrated it is easy to
do any needed instrument corrections in your head. In the "old days"
when LORAN and RADAR were rare on small boats we used echo sounders
for navigation all the time even in pretty deep water.

-- Tom.

Depth sounder calibration
 

wrote in news:4681862b$0$4327
:

I wonder what is the preferred method of calibrating?


Run it aground. Set ZERO. Calibration complete!

Larry
--
http://www.spp.gov/
The end of the USA and its Constitution....RIP

Depth sounder calibration
 

the_bmac wrote in :

I learned to waterski and jump freighter wakes in the Detroit River.
First time I fell I was shocked to be able to stand in neck deep water
1000' from shore...you see in 1968, you couldn't see the bottom in 5'
of water in the Detroit River!!!



My father actually DROVE US through Sarnia, Ontario Chemical Sewage City on
our way to Michigan. I'm amazed when you let go of the rope the skis
actually sunk in the Detroit River in the 60's!

Larry
--
http://www.spp.gov/
The end of the USA and its Constitution....RIP

Depth sounder calibration
 

On 2007-06-28 00:51:08 -0400, Larry said:

wrote in news:4681862b$0$4327
:

I wonder what is the preferred method of calibrating?


Run it aground. Set ZERO. Calibration complete!

Larry

That post should have had a beverage alert! I'm cleaning coffee off my
computer screen now!

Ruby
--
Ruby Vee

Focusing on the negative only gives it more power -- Chinese fortune cookie

Depth sounder calibration
 

"Ruby Vee" wrote in message
news:2007062916192337709-rubyvee3@comcastnet...
On 2007-06-28 00:51:08 -0400, Larry said:

wrote in news:4681862b$0$4327
:

I wonder what is the preferred method of calibrating?


Run it aground. Set ZERO. Calibration complete!

Larry

That post should have had a beverage alert! I'm cleaning coffee off my
computer screen now!

Ruby
--
Ruby Vee

Focusing on the negative only gives it more power -- Chinese fortune
cookie


You got that right.
Good thing with a wing keel.

Depth sounder calibration
 

Ruby Vee wrote in news:2007062916192337709-
rubyvee3@comcastnet:

On 2007-06-28 00:51:08 -0400, Larry said:

wrote in news:4681862b$0$4327
:

I wonder what is the preferred method of calibrating?


Run it aground. Set ZERO. Calibration complete!

Larry

That post should have had a beverage alert! I'm cleaning coffee off my
computer screen now!

Ruby

Oops...sorry! Read our legal disclaimer...(c;



Larry
--
http://www.spp.gov/
The end of the USA and its Constitution....RIP