Acceptable Boat Speed Before SI Interference

[plunker]

If you're SI ducer is mounted to your jackplate you will probably never get SI readings at 10 mph or even over 5 mph. It is simply too high and too much turbulence. Do you have a picture of your SI ducer and mount?

[bobcoy]

Kev, It seems to me the Bass Cats sit slightly bow up at rest or idle,Does it not? Was wondering if when the boat rides more flat in the water at a faster idle if the transducer mounted on the jack plate might be nose down at that point,causing bubbles to run under the ducer. Just a thought. Bob

[BassCatKev]

RFI from the outboard is different at different RPM's. Nothing unusual about that. It's the same with the trolling motor in some cases.

As far as the depth readout, that can be a faulty transducer, poor transducer installation, faulty connections, or faulty unit.
The best way to find out is try another unit connected the same way and try another 2D transducer. You can use another transducer in the bilge with just water making the bond between the transducer face and hull (same as you would do when testing for the best location prior to attaching the transducer to the hull).

Wayne. Regarding testing with another control head, my one and only SI Helix 10 is currently hooked to the Y cable and high speed thru hull ducer. I have 3 other Helix 10s but all are Sonar GPS only. Won't this make them not able to test with since they can't read SI transducer and therefore not be able to tell me whether my high speed ducer is the problem? The previous owner told me he had sent that unit to be fixed when I noticed there was a missing unit on console dash mount when test driving. I wonder now if that was his issue with it and Humminbird didn't fix it. I replaced the y cable and that didn't fix it. So I have 2 perfectly fine y cables now. There is another high speed thru hull ducer epoxied in bilge that was no longer in service when I got the boat. It's connector had been cut so I can't try it. I'm not sure there would be space to put another one.
Do I need to find another SI unit when testing with another unit?

[Wayne P.]

Wayne. Regarding testing with another control head, my one and only SI Helix 10 is currently hooked to the Y cable and high speed thru hull ducer. I have 3 other Helix 10s but all are Sonar GPS only. Won't this make them not able to test with since they can't read SI transducer and therefore not be able to tell me whether my high speed ducer is the problem? The previous owner told me he had sent that unit to be fixed when I noticed there was a missing unit on console dash mount when test driving. I wonder now if that was his issue with it and Humminbird didn't fix it. I replaced the y cable and that didn't fix it. So I have 2 perfectly fine y cables now. There is another high speed thru hull ducer epoxied in bilge that was no longer in service when I got the boat. It's connector had been cut so I can't try it. I'm not sure there would be space to put another one.
Do I need to find another SI unit when testing with another unit?

Well since you have three 2D units, you have three that will connect to the "high speed transducer" to check its performance.

[BassCatKev]

Thought maybe the y cable for side imaging may have something to do with it. A friend switched out my y cable back when I thought that may be the issue. So I've never seen how the hook-up works.

[BrownTrout]

When I take off at WOT my SI screen goes black around 5 or 6 mph. When I'm trolling fast I can see details up to around 7 or 8 mph.