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.