Use case for DFF3D Cross Section?

[OFFLINE]

I have a new install of TZT3, DFF3D, and the 165T-50/200-TM260 multi-beam transducer.

Today’s question: What is the value of the Cross Section view?

On my setup, I see occasional flashes of fish as they go by, but it is difficult to understand how I could use the image to gain any insight to help catch them.

Garmin’s competing product, the PS30 sensor, has a steerable 20 degrees forward and 20 degrees aft real-time view. That means it useful for seeing a lure spread when salmon fishing. You can actually see fish come into the spread and go for a particular bait. You can also see how well the spread is tracking - skewed or directly behind the boat. Nice, useful info.

My multi-beam is only 7 degrees front-to back, so seeing much other than an occasional flash is challenging.

What am I missing in setup or in my use? So far I see little practical value.

 

[Johnny Electron]

@Deep Blue can probably provide more insight. It is what is actively happening below the transducer. I have found if the gain settings get taken way too high, you won't get cross section and 3D history. So I use it as a bit of a troubleshooting tool. If going back over seeking a target it can give you exact moment you get back on top of them for dropping lines.

 

[Deep Blue]

OFFLINE,

The DFF3D's Cross-Section was designed to display real-time sea column echoes (providing the operator with the raw data on what the transducer seeing.) in 120° port & starboard beam width, along with 8° fore & aft beam width. Cross-Section can still be used in detection of baitfish and the distribution of any fish school concentrations within the water column, granted that the fore & aft beam width is narrow.

The PS30 has a beam width 120° x 60° but with only 144 watts of power at 417kHz. So, its overall depth is generally limited to around 300 ft. And with that higher frequency, if you encounter any rough seas it can cut that depth in half. So, these specifications limit the PS30 for near shore capability only, where the DFF3D (having TX power of 800 watts and the lower frequency of 165khz) allows the unit to be utilized for deeper offshore use to around 1000 ft.

There are a lot of Albacore and Tuna guys who are using DFF3D’s Cross-Section to fish.

- Deep Blue

 

[OFFLINE]

Thanks, Deep Blue. I appreciate hearing the design details. I understand a bit better now.

My use case is substantially different from the Albacore and Tuna guys as 95% of the time I’m in less than 350 FOW and am slow trolling 100% of the time, dragging a spread of lures down 40-200 feet. They won‘t show up in an 8 degree beam.

I‘m not regretting going with TZT3/DFF3D system, but I do wish the Cross Section design was better suited for my use.

Just thinking aloud, it might be possible to tilt the transom mount transducer to help capture my spread. Hmmm.

 

[mattology]

I used the cross section to find wrecks, when i knew i was in the area, but i couldn't get it to show up on the 3d history, i would switch to triple beam and cross section and found it that way...