Topic: Drawing a blank

[wheelsville]

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

[sonar2000]

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

[wheelsville]

Check the pic, could I re-mount it in the middle on the last step?

[sonar2000]

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

[wheelsville]

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

[Roddy]

Wheelville, Post a pix of the complet stern of the boat. Roddy

[sonar2000]

Looking at your picture it appears another transducer in front of the HDSI...This will certainly create a bubble or water aeration issue..

Chuck

[ITGEEK]

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.

[wheelsville]

See pic

[ITGEEK]

Based on your picture, the way your transducers line up don't look
too good.

[Roddy]

Wheelsvill, One more pix of all of the stern. Thanks Roddy

[wheelsville]

The other transducer was old so, I took it off.

[sonar2000]

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

[Humminbird_Greg]

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.

[wheelsville]

Do you think the transducer is in the right spot?

[Humminbird_Greg]

Not for depth readings at anything above slow speeds, but it might work for Si sonar readings.

[sonar2000]

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