Humminbird Side Imaging Forums

Side Imaging Forums => 997c SI, 998c SI & 999ci HD SI => Topic started by: wheelsville on March 21, 2012, 10:03:59 PM

Title: Drawing a blank
Post by: wheelsville on March 21, 2012, 10:03:59 PM
Does anyone have a problem with there 998 loosing reading while running down the lake? cant read the depth when in 2d mode?

Thanks,
Shannon
Title: Re: Drawing a blank
Post by: sonar2000 on March 22, 2012, 09:16:19 AM
I think this does happen to some.  There are dependencies that can affect the reading.
1) the type of transducer used
2) the location of the transducer
3) items that can create bubbles in the water during higher speed runs
4)Check your max depth setting and try to set it to a figure somewhat below the actual depths
      (turn off auto depth mode)

Which transducer do you have and can you show a picture of the installation to the boat.

Chuck
Title: Re: Drawing a blank
Post by: wheelsville on March 22, 2012, 10:03:37 AM
Check the pic, could I re-mount it in the middle on the last step?
Title: Re: Drawing a blank
Post by: sonar2000 on March 22, 2012, 10:16:27 AM
Dont know if a relocate will fix your problem. I lean towards thinking it wont..

The HDSI transducers are known to lose depth on speeds above trolling.

Most have elected to add an inhull shoot thru the hull for higher speeds and depth.
Many posts on this forum with just this issue..
Chuck
Title: Re: Drawing a blank
Post by: wheelsville on March 22, 2012, 10:44:49 AM
That's what I had heard, I was thinking about getting a cheaper unit just for reading my depth while running, BTW this forum is bad ass! Thanks for all your help!!

Shannon
Title: Re: Drawing a blank
Post by: Roddy on March 22, 2012, 10:46:26 AM
Wheelville, Post a pix of the complet stern of the boat. Roddy
Title: Re: Drawing a blank
Post by: sonar2000 on March 22, 2012, 10:47:20 AM
Looking at your picture it appears another transducer in front of the HDSI...This will certainly create a bubble or water aeration issue..

Chuck
Title: Re: Drawing a blank
Post by: ITGEEK on March 22, 2012, 11:00:50 AM
You have to realize too that depending on how powerful your motor
is, and how fast your boat goes:
The transom may lift up so high that the only thing in the water at the
back of your boat is the propeller.
If that's the case, the transducer won't be able to work.
You can try lowering it as low as possible, but again, depending on what
speed you go, you may have too much turbulance around it for it to
work properly.
You could even tear the transducer off the boat if the speed is excessive
and it's not angled properly.  Also, too low and you might hit an object.

I'd go with the shoot thru like Chuck recommended for high speed depth
readings, then switch over to the traditional for normal use.
Title: Re: Drawing a blank
Post by: wheelsville on March 22, 2012, 11:07:09 AM
See pic
Title: Re: Drawing a blank
Post by: ITGEEK on March 22, 2012, 11:12:57 AM
Based on your picture, the way your transducers line up don't look
too good.
Title: Re: Drawing a blank
Post by: Roddy on March 22, 2012, 11:21:58 AM
Wheelsvill, One more pix of all of the stern. Thanks Roddy
Title: Re: Drawing a blank
Post by: wheelsville on March 22, 2012, 12:03:24 PM
The other transducer was old so, I took it off.
Title: Re: Drawing a blank
Post by: sonar2000 on March 22, 2012, 12:09:39 PM
OK, that was a good idea.

I really think you should look at a thru the hull for depth at speeds.

It is just the way the large HDSI transducers work with speed. (or dont work) ::)
Depending on motor thrust and plane level it could raise the transducer out of the water.  You can check that next time on the water..

Chuck
Title: Re: Drawing a blank
Post by: Humminbird_Greg on March 22, 2012, 04:56:46 PM
Yep, with that boat hull I also think that an XP-9-20 inside-the-hull mounted transducer and an AS-Si-DB-Y cable is the way to go.

Title: Re: Drawing a blank
Post by: wheelsville on March 23, 2012, 08:32:47 AM
Do you think the transducer is in the right spot?
Title: Re: Drawing a blank
Post by: Humminbird_Greg on March 23, 2012, 01:15:48 PM
Not for depth readings at anything above slow speeds, but it might work for Si sonar readings.
Title: Re: Drawing a blank
Post by: sonar2000 on March 23, 2012, 07:44:08 PM
I doubt that si will be of any value at speed..but that is normal.....   SI is normally best at 1 to about 5 knots..

chuck
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