RE: [PSUBS-MAILIST] Sonar

["Gary R. Boucher" <protek@shreve.net>]

Rob,
     Yes, I have used one to look forward and I have known of others that 
have also.  However, one warning; If you allow the unit to be in AGC mode 
or whatever they call it, where it is allowed to adjust its own 
sensitivity, it will adjust its gain until it sees something.  Once I was a 
little less than 30 feet deep and I began to see the unit reporting 28 feet 
to an obstacle.  It continued to see the 28 feet for some time even through 
I was moving forward.  Since there were no obstacles ahead and I was in 130 
feet of water, I finally figured that the gain had adjusted automatically 
to the point where it was seeing the surface.  I would try setting the gain 
to manual and experimenting with it till you don't see things that are not 
there.  One other thing is the fact that my unit defaults to the auto mode 
every time you power up.  So if I shut it down, I had to reprogram it into 
the manual mode.  Might research one that does not need this done each time.

Gary Boucher

toAt 03:09 AM 4/25/01, you wrote:
>Pat,
>
>Is it possible to use a fishfinder as a forward looking sonar?  I know I
>would like to "see" 20-30 ft in front via sonar when there is no/limited
>visibility - at least you have some time to reverse and avoid things like
>submerged logs or obstacles.
>
>-Rob