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?

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

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

"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.

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

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/

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

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

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

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