Topic: 999 doesn't show bottom above 10 mph

[brents89]

I have just bought a boat with the 999 ci HD SI unit installed. I noticed that when I would go over about 8 mph the unit would lose the bottom. I was told it needed a second transducer to work at higher speeds so I had one installed. It was a little better, but still lose bottom after about 10 mph. SI, DI and 2d all seem very good at trolling speeds up to approx. 5 mph, but then deteriorate as speed increases.  I was told the transducer may need to be adjusted, but any additional thoughts would be appreciated.
Thanks

[Bob B]

What boat do you have .... pictures of the transom from various angle will help.

The transducer has to be located where it will have smooth water flow without bubbles .... sonar won't shoo thru the air in the bubbles.

[newkid4si]

Are you still viewing the SI or DI page at the higher speed when you lose bottom readings?   If so, switch to the 2D page and see if the bottom reading is still shown.  If the 2D isn't shown, a 
transducer adjustment is needed. The SI and DI are not designed to work at high speeds and those speeds are about when you stop seeing the images.


           Mike

[brents89]

Sorry i didn't specify but the picture was taken with 2D on. I took another look at the transducer and believe that the back may need to be adjusted down one notch. As the snow is starting to fly, I think this won't get tested until next spring. Thanks for the replys.

[rnvinc]

A transom mount xducer should be mounted as indicated in the diagram below ...


Rickie

[newkid4si]

I would add that after leveling the bracket as in Rickie's illustration, I have found that my high speed images (2D) improve with the rear of the transducer slightly lower that the front edge.

         Mike