Re: How about fish finders?

[Derek Andersen <deanders@pcisys.net>]

Ever since I started looking at homebuilt subs, I've been looking for a
good forward-looking sonar; while I'm sure that mounting a normal fish
finder so that it looks forward and down would work, it's not what I want.
So far, though, I've only found one company that offers them (Interphase,
www.interphase-tech.com), but I'm still looking for others. Has anyone else
found any companies offering forward-looking sonar?

Derek Andersen


>    About the fish finders...  I have mounted one on my sub looking down
>and forward also.  They do work and will take probably much more than 50
>feet of depth.  However, one caution.  Most have automatic gain control in
>one form or the other.  If looking forward and they do not see the bottom
>they turn up the gain.  This results in very very sensitive reception.  I
>once noticed that I kept seeing 18 feet on mine even when I was moving.  I
>looked at the depth gage and I was 18 feet deep.  It was so sensitive that
>it was recording surface echos.  Get one you can set to a manual gain
>value.  Problem is this; every time you turn it off you have to go and
>reset it and it takes a minute or two.
>
>Gary Boucher
>
>