Kayak Sonar Discussion

[acorad]

Great thread! I bought a FF last year, but have never used it.

This is giving me the motivation!

Need to get an over-the-side arm for the transducer...

Andy

[NICKWORN]

Originally Posted by Dannowar

DORADO. YOU'RE BITTTTTTT




Open for interpretation....


Sent from my iPhone using Tapatalk

That looks like Jims boat!!

[chris138]

Originally Posted by Dirty Curti

Thanks for the thread. I have a few images I would like to share and get your opinion on what you see. I didn't catch any fish during these meter reads.


Thanks for any input.

Thanks for checking in. First off, were these taken in La Jolla near the corner or somewhere with similar structure? The reason I ask is some of it looks like kelp to me. But if you were in a sandy area with no kelp around I might reconsider.

#1: settings look really good in this one. To me this looks like a big school of fish... not huge fish but not tiny bait either. I've seen big schools of sandbass and calicos mark like this. Also, over rocky reef areas, you will see ocean whitefish and blacksmith perch look like this. Blacksmith or whitefish would explain why you never got a bite. I've seen big schools of yt look kinda like this, but they would be harder marks with a lot more bright reds and yellows in there.

#2: Sensitivity is way too high for that depth, need to dial it back a lot. Tough to tell what is there with all washed out like that, but I think I see your dropperloop or some bait down. And probably some baits and small fish checking it out.

#3 setting looks great. here we have a big vertical strand of kelp in the middle, and a couple of good wads of mackerel feeding at about 20-25'. Also some scattered debris and probably rockfish on the bottom. here you should be working that sibiki shallow, they look like good greenbacks or big spanish.

#4: shallow water again. Your sensitivity is a little hot, but much better than #2. The big worm in the middle is marking too soft to be a fish. With your gain up that high (bottom is super hot and top ten feet are washed out), a big fish or mammal would come back bright yellow in that shallow. However, in the bottom left of the shot, there looks like there was a good little wad of fish on the bottom. Could be some corvina, mackerel or small bass or something along those lines.

[makobob]

Looks like Jim's boat and it has been Baja tested and PASSED. Tight line amigos.

[steveooo]

What are these? Are they tasty?

















































*edit* chewy jacks

[ful-rac]

They look like PANCAKES stacked up like PANCAKES!

[Denis_Ruso]

explain to me why I still cant get a bite

[goldenglory18]

My Dragonfly 7 pro is getting a soft install Friday and I'm so stoked. I'll be taking it out for a quick paddle on Sat for a final adjustment before final hard install with in-hull wiring and plastics painting.

I can't wait!!!

[chris138]

Originally Posted by Denis_Ruso

explain to me why I still cant get a bite

I think you need to wiggle your bait more dude

[Orca Winfrey]

Originally Posted by acorad

Great thread! I bought a FF last year, but have never used it.

This is giving me the motivation!

Need to get an over-the-side arm for the transducer...

Andy

Or just go with a friend who has one and knows how to read it.

[acorad]

Originally Posted by Orca Winfrey

Or just go with a friend who has one and knows how to read it.

Yep.

Andy

[Dirty Curti]

Originally Posted by chris138

Thanks for checking in. First off, were these taken in La Jolla near the corner or somewhere with similar structure? The reason I ask is some of it looks like kelp to me. But if you were in a sandy area with no kelp around I might reconsider.

#1: settings look really good in this one. To me this looks like a big school of fish... not huge fish but not tiny bait either. I've seen big schools of sandbass and calicos mark like this. Also, over rocky reef areas, you will see ocean whitefish and blacksmith perch look like this. Blacksmith or whitefish would explain why you never got a bite. I've seen big schools of yt look kinda like this, but they would be harder marks with a lot more bright reds and yellows in there.

#2: Sensitivity is way too high for that depth, need to dial it back a lot. Tough to tell what is there with all washed out like that, but I think I see your dropperloop or some bait down. And probably some baits and small fish checking it out.

#3 setting looks great. here we have a big vertical strand of kelp in the middle, and a couple of good wads of mackerel feeding at about 20-25'. Also some scattered debris and probably rockfish on the bottom. here you should be working that sibiki shallow, they look like good greenbacks or big spanish.

#4: shallow water again. Your sensitivity is a little hot, but much better than #2. The big worm in the middle is marking too soft to be a fish. With your gain up that high (bottom is super hot and top ten feet are washed out), a big fish or mammal would come back bright yellow in that shallow. However, in the bottom left of the shot, there looks like there was a good little wad of fish on the bottom. Could be some corvina, mackerel or small bass or something along those lines.

Great info thanks.

This is near the pipe in carlsbad.

Your comment regarding the "big worm" in photo 4 is to soft to be a fish. That confuses me because this is what I would expect to see if there is a larger fish under the kayak. So you said that if it was a bigger fish in water that shallow that I would see bright yellow color in the mark?

Also, Is there a way to understand a mark being on the left or right side of the kayak? Or where you should be casting when marks show up?

[chris138]

Originally Posted by Dirty Curti

Great info thanks.

This is near the pipe in carlsbad.

Your comment regarding the "big worm" in photo 4 is to soft to be a fish. That confuses me because this is what I would expect to see if there is a larger fish under the kayak. So you said that if it was a bigger fish in water that shallow that I would see bright yellow color in the mark?

Also, Is there a way to understand a mark being on the left or right side of the kayak? Or where you should be casting when marks show up?

Yes. The purplish return that you see there is probably some kind of kelp or debris floating midcolumn. If you were in 140' of water and saw that mark, I would say it might be a fish. But for how shallow you are in that pic, and how high your gain is set, a hard-bodied object would come back yellow, if not bright red/orange. Some may disagree with me... it's only my opinion.

You really can't tell which side of you the fish is on for the most part. I should note that its not impossible to tell, but its a very advanced technique without sidescan. The technique must be done with dual frequency, and requires a sideways oriented drift. The two sonar cones are not identical, and you can infer information from the overlap of the two signals. So if you drifted directly over an object (assume it's stationary) it would show up on 83 kHz first, then it would show up identically hard on both frequencies, then disappear from 200 and only be on 83 again. At this point you would know the object was on the upwind side as you drifted directly over it. If you practice this technique often, you can start to predict when the object will take this path. So once you just barely start to get the return on 200kHz, you can infer that it is down-drift from you.

Anyone follow that?

You can also slowly zigzag across an area and make similar inferences. Like I said, it's an advanced technique and takes 100's of "sonar hours" to be effective.

I had an idea for an invention which would have a dual spectrum return that could differentiate between port and starboard orientation. Anyone know an acoustic engineer?

[GregAndrew]

Originally Posted by chris138

Hey Gang,

I feel like a lot of people have the same kinds of questions when it comes to sonar... Especially from those folks who have just recently got their first fish finder, or have upgraded or switched brands. In internet forums, you typically want to avoid having a bunch of different threads about the same topic. It makes it hard for people to go back and search for the info they need.

Some of you who have followed me for a while know that I like to offer sonar tips to fellow kayakers when I can. So I thought I would start my own sonar thread, and try to make it more of a centralized location for some of this info.

The format I envision is that people can ask some of their sonar questions here. I'll do my best to check in often, and answer the best I can. Other more experienced members should chime in and address whatever they want, or tear my theories to shreds if you want... I can take it don't worry (;

What the thread is NOT for: Put-downs or trolling others, arguing with others about which brand or product is better than another, online deals or people trying to sell their stuff. I use Lowrance, but I will not try to sell their stuff or try to convince you that it is better than another product. This should be the place for technical discussion and sonar theory.

I'll kick it off with a few sonar tips for beginners, and a few screen shots from my IG archives


1. Try to mount the transducer in the water. Yes, shooting through the hull works, especially if installed by experts like the guys at OEX. I've done it both ways with the same FF and trust me you are losing sensitivity and signal strength. I would go with a RAM boom arm over a through-hull install every time.

2. Use separate power supply for FF and bait tank. This is for obvious reasons, if one system goes down you don't lose the other device. An entry level sonar like an Elite 4x for example uses very little amperage without GPS. The pump will drain batteries fast, especially 12V. Learn how much juice you need for your setup, and size your batteries appropriately.

3. Stuff will corrode, and need to be repaired. Next time you're at OEX or west marine, buy a bunch of extra terminal connectors, heat shrink butt connectors, and wire. Have all that stuff with you at the launch so when your sonar doesn't turn on, you can repair it right then. Make your wiring easily accessible and give yourself extra slack in case you have to cut and reconnect.

Now the "plotter porn"

Kamakazi Yellowtail!



Fatty Homeguard Dives on my Dropper.



Slug Halibut Stacked Like Pancakes!



Looks like WSB to me... what do you think?



School of YT breezing through mid column, out on the periphery of the cone.

I would have a few different interpretations on these.
Photo 1, I would agree with.
Photo 2, could be a YT, WSB or even a Sea Lion. I would go with what I caught or saw.
Photo 3, I would not guess Halibut unless you have your colorline very high. They are a demersal fish with no swim bladder and generally don't mark in hard colors (like many sharks and rays). I would guess YT or WSB.
Photo 4, By the thickness of the mark at that depth I would lean towards YT, but it could be a WSB.
Photo 5, By the depth and thickness of marks I would guess good sized Macks, Bonito or small YT.

Originally Posted by Dannowar

DORADO. YOU'RE BITTTTTTT




Open for interpretation....


Sent from my iPhone using Tapatalk

Photo 1, I can't pick out anything but bait in that pic.
Photo 2, The mark on the bottom appears to be a large fish, but I would bet it is a tightly grouped school of smaller fish. The broken edges of the mark over the entire length indicate that.

Originally Posted by Dirty Curti

Thanks for the thread. I have a few images I would like to share and get your opinion on what you see. I didn't catch any fish during these meter reads.

[IMG][/IMG]



[IMG][/IMG]



[IMG][/IMG]



[IMG][/IMG]

Thanks for any input.

Photo 1, Looks like a bait ball of either Spanish or Blacksmith (judging by individual mark size and coloring).
Photo 2, You are on the wrong frequency and over gained in that depth of water.
Photo 3, Mixed species school of bait, or could be some smaller predators among them.
Photo 4, That mark looks like a fish to me. I would guess that it is either a fish with no swim bladder or it is staying just outside of your transducer cone angle, or both.

Originally Posted by steveooo

What are these? Are they tasty?

















































*edit* chewy jacks

Perfect example of cone angle. The arches that are Red and solid are moving directly through the cone angle. The ones that remain blue and broken are outside the cone angle. The thickness of the bars, in the cone, are just the right size for the depth of water to match YT.

Originally Posted by Denis_Ruso

explain to me why I still cant get a bite

I can show you hours of video footage on fish not biting. Almost all of it can be attributed to a sluggish or oddly moving bait.

[chris138]

Originally Posted by GregAndrew

I would have a few different interpretations on these.
Photo 1, I would agree with.
Photo 2, could be a YT, WSB or even a Sea Lion. I would go with what I caught or saw.
Photo 3, I would not guess Halibut unless you have your colorline very high. They are a demersal fish with no swim bladder and generally don't mark in hard colors (like many sharks and rays). I would guess YT or WSB.
Photo 4, By the thickness of the mark at that depth I would lean towards YT, but it could be a WSB.
Photo 5, By the depth and thickness of marks I would guess good sized Macks, Bonito or small YT.


I can show you hours of video footage on fish not biting. Almost all of it can be attributed to a sluggish or oddly moving bait.

Hey Greg, thanks for chiming in! You have a very unique perspective of sonar returns, given your awesome video vantage. Most of the time when I claim a species, it's because I was bit on those marks. But not always...

I agree on #3, i happened to get a halibut at the time, however there were lots of YT around as well so you could be correct.

#2, Looks very much like a dog. But I got crushed by a 30# yt on that mark. I actually got the gopro footage of the mark, as it was diving then the bite on video. Edit will be coming...

#4, could be yellow but a little "wormy" for me. This was on a day when all three slam species were around.

#5 agree... could be boney. But a nearby friend caught yt right after so that was the basis of my assumption. And you are correct about them being smaller grade... 15-20#s.

Greg makes a great point here. The only time you know for sure what the mark was, is when you catch off the mark. The first time you do this, and watch the fish hit your bait, you will gain a profound sense of accomplishment and confidence!

[chris138]

Originally Posted by steveooo

What are these? Are they tasty?



*edit* chewy jacks

PREFACE: no disrespect intended SteveOOO. Thanks for posting! Purely my opinion and I could be completely full of it...

To me, these marks don't look like fish. Not sure that I know exactly where this is, but looks to me to be an outside rocky kelp ledge area. Bull kelp zone.

Note the symmetry and length of the marks. See how they are vertically stacked and all similar length, thickness, and heat. I see how both the "head" and the "tail" of the marks are all very similar, and taper off to a pointy tip, without much change in depth. To me this is indicative of stationary objects, or something that is drifting passively in the current. Yellowtail seldom sit still, and are usually very erratic looking and asymmetrical. The marks will look all "tangled" as the fish change depth and react to each other.

This looks like a deep kelp ledge with a good amount of current, and bait in the bull kelp pinned down to the bottom. No doubt prime YT feeding grounds and epic conditions. Cheers boys!

[steveooo]

Originally Posted by chris138

...Not sure that I know exactly where this is...

That was LJ, out in the sandy squid grounds. We caught yoyo YT off it.

One sonar setting that is worth putting into the discussion is Sonar Scroll Speed. It doesn’t change what you see on the meter, but it does change how it appears on the meter. I find setting a faster scroll speed will give me more of a real time picture of what is under the boat. It also gives more defined, and longer individual fish arches. Our kayaks move relatively slow, and sometimes we are chasing fish that move relatively fast (YT). I think of the slower scroll speed as the history channel, or “old news”, where sometimes what is shown on the meter is long gone, but it just hasn’t left the screen yet.

The best time to experiment with this setting is when making bait. With the new chirp units, adjusting scroll speed to a higher setting can make a bait ball go from looking like a cloud, to showing hundreds of individual tiny arches. IMO thats too much clutter for just making bait, but turning up the scroll speed also does the same for a school of YT, turning that mess of squiggly spaghetti hanging out under the kayak into more defined individual fish.

Fast scroll speed is my preference when yoyo fishing. When its there, its there. When dropper loop fishing or fishing for structure oriented fish, I’ll turn scroll speed back to normal, so I don’t blink and miss anything or leave an area prematurely. Normal or slower scroll speed is also good for giving a little more history of what the fish is doing under the kayak, e.g. showing a YT dive bombing your bait. Its really a matter of preference of how you want the fish & screen to look.

*disclaimer* I’ve caught many more fish through dumb luck than I have by using my sonar.

Good thread

[Sheephead]

Great thread idea Chris! I love how your naming your sonar marks too!



For the first two pictures I'd like to welcome everyone to the promised land.

The third picture is a good example of how bait reacts to a school of yellowtail. Even if your not marking yt if you see bait behavingg this way you can tell if fosh are around.

Lastly, the 4th pic shows a single yt swimming through a small school of red crab. Yes my settings suck! For yhe 4th pic.

[TJones]

Originally Posted by chris138

Yes for sure you can. Sometimes the key with that is the color line. Play around with colorline until you get the kelp to mark really soft, then the fish or bait will stand out more. I also like downscan 455 kHz for this application, because you can see the individual kelp strands and a fish really sticks out.

If you can get the DS dialed in, then you can overlay it on top of your mid/high chirp... for a more advanced configuration.

.

[summers in kuwait]

Thanks for the details Chris!
This is going to be a great thread for info... and fish finder porn!