FCV588 P66 Losing bottom LF side

[19mal71]

Hi was out today good weather travelling trolling speed had good solid bottom on HF side but LF had clear breaks in the bottom any ideas. Running FCV 588 and P66 transducer

 

[Snips]

19mal71,
Thanks for the screen shots
Looks like a classic case of turbulence. I would be willing to bet it changed based on speed and if you were turning also. In most cases, turbulence will affect the LF side first and gets worse at higher speeds. Transom mounted transducers are more susceptible to turbulence than a transducer that uses a fairing block. Below is a screen shot of turbulence from a difference sounder. One thing to note is how it affected the HF side also. While you still can see the bottom, all the water column targets were eliminated.

Can you post how you mounted your transducer?

Snips

 

[19mal71]

Thanks Snips was slightly worse when turning . I thought the middle shot shows suspended bait on both screens all be it weaker on LF with clear bottom break on LF

 

[19mal71]

Hi Snips have attached photos of my transducer position.

 

[Snips]

19mal71,
Looks like it is mounted between two lift strakes?
That lower one is going to cause a turbulence.

Can you post a couple more photos of the transom showing the transducer, that lower strake and the motor?

Snips

 

[19mal71]

Hi snips fairly central on Straker, outboard is on a pod so behind transducers

 

[Snips]

19mal71,
Thank you for the additional pictures.
The optimum location for any transducer is as close to the center line as possible. This puts the transducer at the lowest (deepest) part of the hull and in an area that normally has less turbulence. In your case you already have a transducer in the #1 location.

So you have three options going forward.
1. You can adjust the depth and angle of the P-66 in it's current location to see if that
helps. However due to it position to the strake I don't think it will help very much.
2. Your other transducer looks to be a down view (side scan) which means it is going to be
high frequency, maybe in the 200-400Khz range. These transducers can tolerate more
turbulence than 50Khz can. So option two would be to switch transducer locations.
3. Move the P-66 to the port side. I see that your transom has pre-made brackets to
attach transducers to. So even though it is on the port side it will be lower and inside
that strake.

Snips

 

[19mal71]

Ok thanks Snips ,what would you recommend in a 1kw transducer if I were to upgrade, which would give me best possible results?

 

[Snips]

19mal71,
If I was going to recommend a 1kw ducer it would be a B-260 on a fairing block.
Personally I try to stay away transom mounted transducer for the very reason you are currently encountering.

Snips

 

[19mal71]

Yep ok thanks for the help stay well

 

[Deep Blue]

19mal71,

When it comes to turbulence, this is probably what you are fighting against and why you are experiencing bubbles:


This is why transducer placement is so very critical to the heart and soul for any Echo Sounder installation.


-Deep Blue