Sonar Interpretation

[TMan]

Hey there.
Since so many people here run all sorts of sonar and have a lot of time on the water, does anyone have a good set of pictures they would be willing to share to help guide some of us less knowledgeable people?
I was thinking, baitfish....herring vs sandlance, krill clouds, anchovies etc.
Rockfish/cod as well.
I hear that some sounders when set right can even pick up prawns on the bottom.

My knowledge is limited to really obvious bait schools and salmon. It works for me, but any advice or pics might be useful and help my game.

Thanks,
Trevor

 

[Steplift]

I fall somewhere in between which makes my knowledge level dangerous lol. I run a basic model lowrance chirp that works well enough for me. You can clearly see the down-rigger ball slicing through bait balls. There are several arcs underneath them, which are feeding coho. The bottom here was solid rock. I have seen crab balls before on the bottom and other lifeforms that may be squid not really sure. i’ve never had the pleasure of fishing with somebody with a higher end sonars

 

[TMan]

View attachment 107412I fall somewhere in between which makes my knowledge level dangerous lol. I run a basic model lowrance chirp that works well enough for me. You can clearly see the down-rigger ball slicing through bait balls. There are several arcs underneath them, which are feeding coho. The bottom here was solid rock. I have seen crab balls before on the bottom and other lifeforms that may be squid not really sure. i’ve never had the pleasure of fishing with somebody with a higher end sonars

That's and awesome photo. Thanks for sharing that. It kind of has it all. Do you normally run Med or High chirp? I have been finding that med chirpmlets me.see my gear a bit better. But maybe that is because I've used a lighter ball lately and it exiting the high chirp cone.

 

[sly_karma]

This is tightly packed schooling coho over a rock bottom.

 

[Steplift]

That's and awesome photo. Thanks for sharing that. It kind of has it all. Do you normally run Med or High chirp? I have been finding that med chirpmlets me.see my gear a bit better. But maybe that is because I've used a lighter ball lately and it exiting the high chirp cone.

I run on high chirp and switch it to slow trolling mode while not on plane and seem to get a clearer picture. Again not anywhere close to an expert on the matter. Try going into the setting on your sonar and change them to match your speed and depth.

 

[TMan]

I'll try that.

 

[sly_karma]

I understand there are occasional info sessions at stores, given by tech reps from the sonar makers. It would be great to go to one of those. I figure I'm probably only using a third of the capabilities of my units.

 

[Steplift]

I understand there are occasional info sessions at stores, given by tech reps from the sonar makers. It would be great to go to one of those. I figure I'm probably only using a third of the capabilities of my units.

YouTube is a great resource on this topic googe your model. I think I spend more time researching stuff than actually fishing.

 

[sly_karma]

YouTube is a great resource on this topic googe your model. I think I spend more time researching stuff than actually fishing.

I've watched some for sure. But I'm an old fashioned guy, I find the interaction and Q&A of an in-person session is the best way to learn.

 

[Steplift]

I've watched some for sure. But I'm an old fashioned guy, I find the interaction and Q&A of an in-person session is the best way to learn.

And that’s the best part about this forum. There is no lack of information and sharing of it. The knowledge of the history and fishery that a lot people have here is truly amazing.

 

[Sharphooks]

I’m in the crowd that thinks chasing arches is over blown and oversold.

Meanwhile, if you really want to see what the bait is that you’re seeing on your fish finder, put a Sabiki jig on and put all doubt to rest

I once saw the mother of all bait balls——herring, it’s gotta be herring I remember thinking. I tacked my gear back and forth through the billows of bait….nada. I finally put a Sabiki jig on and lo and behold….they were juvenile rockfish—-a squadrillion of them.

I was an early adopter of CHIRP and DFF 3D. But day in and day out, my favorite transducer is an old-school P-66 50/200 KHZ 600 W skimmer that I bought on eBay for $ 50

This morning I saw a bait ball. Zero arches, no suspicious “blobs” that everyone raves about seeing that they know are predators. I dropped my gear down on top of it—-instant take down ….thanks Mr. P-66

So, after I got that fish I decided to take some screen shot comparisons

First picture is a TM165HW Chirp (on the left) and the DFF3-D triple beam on the right

The gain setting were reasonably similar but one transducer is on the starboard transom and the other is on the port—-different placement, different target returns




Here’s the same (exact same) bait ball as seen by the P-66 CW transducer (Continuous wave = non CHIRP) hooked up to a Furuno FCV 588 with Rez Boost (which is also known as poor-man’s CHIRP)





What is that suspicious arch we see in all three screen shots? I once asked a Furuno technician who had agreed to come out with me on my boat and show me his bag of tricks that same question—-what’s that arch I asked.


Oh, we call those targets was his response.

Moral of the story…..don’t over-think sonar technology. Find the bait and sooner or later, you’ll find what’s eating it

I was once fishing Big Bank (La Perouse) This was back in the days when there were masses of sardines out there

One morning I was out there in mid July. The fishing was absolutely ridiculous —- double header after double header, non-stop. Everyone around me was also getting what I was getting. I had a CHIRP B175HW and also an M260 (1 Kw in-hull transducer ) With all that fire power I was floored that all I could see were sardines. No arches, no blobs, and it was literally chinook city beneath my boat. Yes, I tweaked the settings

So I took that day as a teachable moment on how to approach sonar technology

 

[Samnjoe]

I use the sounder mostly to avoid losing cannonballs.

 

[TMan]

I use the sounder mostly to avoid losing cannonballs.

That's pretty reasonable actually.

 

[RiverBoy]

here’s what two diving humpback whales look like sounding dangerously close to your stern: couldn’t believe how deep they got so fast.

 

[Whole in the Water]

Seeing a bait ball and some fish arches can be encouraging. However 99% of all the fish I have caught in saltwater in over 25+ years have been when there are zero fish arches on the screen and I have always had good quality equipment. I too think seeing fish arches in the saltwater is overblown.

 

[jackfish]

The Raymarine live guy is running a special episode on this topic June 25. He will post it to youtube after that. Although it is based on raymarine gear, I think most of the info is generally applicable and he's an amazing technical resource. (I'm not plugging raymarine...just sharing some info!)

 

[Salty338]

Given that I jig exclusively I guess I have a different take on it. I want to see arches. Honestly, even if I see bait that has no fish in it or at the very least see that the bait is disrupted in some way like a fish has smashed through it, I don't waste my time dropping a jig. Too many times I've stopped in huge baitballs that have not showed any fish on the screen and got blanked. If there are active fish in it, they will show and more often than not when I target the ones I see, we hook up.

 

[RiverBoy]

Seeing a bait ball and some fish arches can be encouraging. However 99% of all the fish I have caught in saltwater in over 25+ years have been when there are zero fish arches on the screen and I have always had good quality equipment. I too think seeing fish arches in the saltwater is overblown.

agree 100%. i’m jigging blank screens right now in CR and getting coho lings and springs. not one stitch of bait or anything present

 

[Salty338]

Curious to know what the setups are? I absolutely have caught fish when there was nothing on the screen. Currently I’m running Lowrance with their 3in1 transducer but just ordered an Airmar to add on.
When I see this under my boat it’s go time and when it’s like that things happen fast. Really fast!

 

[Salty338]

Curious to know what the setups are? I absolutely have caught fish when there was nothing on the screen. Currently I’m running Lowrance with their 3in1 transducer but just ordered an Airmar to add on.
When I see this under my boat it’s go time and when it’s like that things happen fast. Really fast!
View attachment 107466

And that’s not the bottom at 90’ it’s bait pushed down showing a false bottom in roughly 150’ of water.