Learning To Find Structure: Side View Sonar

[redboat]

After several years of "beating the banks" I've decided that in order to progress as a bass angler I'm gonna have to learn to fish structure. I read the excellent series "So you want to learn to fish Toledo Bend, picked up some excellent tips from Catt and the guys posting on that thread.

I went out with a guide on lake Fork summer before last - when it still had water in it. He explained about using crankbaits, C-rigs, and Texas rigs to fish submerged bridges. I learned a lot; mainly that my retrieve was way too fast. Next step was learning to find structure.

Last year I bought a Humminbird side view sonar unit. I also upgraded to the latest Navionics PC mapping software; I have the 2008 Navionics chip in the 'bird. I've been using the combination of detailed lake maps and side view sonar to locate some of the underwater structure on Fork.

What I do is, mark the various bridges on the Navionics PC software, upload to a MMC chip, then put this in the Humminbird. The points I mark transfer to the GPS map. Then I go out on the lake and use the side view to find the precise location of the bridges and culverts. The Humminbird has a function that allows you to capture the screen and download to the MMC card as images.

Here are some side view pics I took in October on Fork. Maybe this will help anyone who's thinking of buying a side view unit. In my opinion this thing is light years beyond traditional sonar. I'm still learning how to use the side view but so far results are good.

Bridge over a creek, on the right about 40 feet

Another creek bridge, collapsed pilings on the left

This bridge was a little easier to find with the lake down seven feet.

[waskeyc]

Great post. Although I've never used sonar for fishing, I have used ultrasonics at work for performing inspections. Before I read up on sonars a bit, I always assumed "fishfinders" used a phased array of ultrasonic transducers to create a 3D map of the bottom. It appears however, that phased array technology has not made it to the bass boat.

In the mean time, this sideview stuff is great. Without it, it seems to me that a sonar is little more than a fancy depth finder. Having to pass directly overtop of an area in order to see it on the screen seems like a huge drawback of single-sensor units. What do you do when the water is shallow? How do you keep from spooking the fish? How can you tell what's under a dock or downed tree? What if the item you're looking for is small, but your beam angle is wide and the water is deep?

Sideview provides a great benefit to sonar users.

[Wayne P.]

waskeyc, shallow fish are no problem. This is a screen shot of a lake upper end creek channel with bait fish and bass that had moved there due to a heavy summer rain that cooled the water in that area. Note the depth. I caught two of the bass (white streaks at the top right). The bait fish is the fuzzy white blob in the creek channel at the middle right side of the view. The creek is the darker area caused by the sonar beam not seeing down in the creek channel due to the angle.

I "sight fish" all year in all depths using SI. "It's so easy a cave man can do it"

[Fishing Rhino]

Here's another tidbit. When you are prowling around, studying the bottom, pay attention to what I call transition bottom. It may be a change in the bottom composition, muddy, rocky, sandy, gravel, etc. It can also be a transition in depth (structure) or a transition from bare bottom to bottom with vegetation. Articles frequently refer to fishing the edges of weed beds which is a transition area.

When you are catching fish, pay very close attention to the image on the screen, the bottom line in particular. Is it rough and jagged, wide or narrow, etc. When you've cleaned out that area, find another like it in approximately the same depth.

Nearly thirty years of commercial lobstering taught me a lot about studying the bottom. Unlike fish, lobsters never show up on the image, except for those that must be returned because they are too small or egg bearing lobsters. Then you might see them sinking to the bottom if they pass through the cone of the sounder.

[Wayne P.]

Here's another tidbit. When you are prowling around, studying the bottom, pay attention to what I call transition bottom. It may be a change in the bottom composition, muddy, rocky, sandy, gravel, etc. It can also be a transition in depth (structure) or a transition from bare bottom to bottom with vegetation. Articles frequently refer to fishing the edges of weed beds which is a transition area.

When you are catching fish, pay very close attention to the image on the screen, the bottom line in particular. Is it rough and jagged, wide or narrow, etc. When you've cleaned out that area, find another like it in approximately the same depth.

Nearly thirty years of commercial lobstering taught me a lot about studying the bottom. Unlike fish, lobsters never show up on the image, except for those that must be returned because they are too small or egg bearing lobsters. Then you might see them sinking to the bottom if they pass through the cone of the sounder.

Hard bottom to weeds looks like this with Side Imaging:

[Wayne P.]

Hard bottom areas return stronger sonar pulses and that shows up as brighter areas on the bottom:

[Wayne P.]

After several years of "beating the banks" I've decided that in order to progress as a bass angler I'm gonna have to learn to fish structure. I read the excellent series "So you want to learn to fish Toledo Bend, picked up some excellent tips from Catt and the guys posting on that thread. I went out with a guide on lake Fork summer before last - when it still had water in it. He explained about using crankbaits, C-rigs, and Texas rigs to fish submerged bridges. I learned a lot; mainly that my retrieve was way too fast. Next step was learning to find structure. Last year I bought a Humminbird side view sonar unit. I also upgraded to the latest Navionics PC mapping software; I have the 2008 Navionics chip in the 'bird. I've been using the combination of detailed lake maps and side view sonar to locate some of the underwater structure on Fork. What I do is, mark the various bridges on the Navionics PC software, upload to a MMC chip, then put this in the Humminbird. The points I mark transfer to the GPS map. Then I go out on the lake and use the side view to find the precise location of the bridges and culverts. The Humminbird has a function that allows you to capture the screen and download to the MMC card as images. Here are some side view pics I took in October on Fork. Maybe this will help anyone who's thinking of buying a side view unit. In my opinion this thing is light years beyond traditional sonar. I'm still learning how to use the side view but so far results are good. Bridge over a creek, on the right about 40 feet Another creek bridge, collapsed pilings on the left This bridge was a little easier to find with the lake down seven feet.

redboat, when the Mark button is pushed with the Snaphot feature turned on, that snaphot is saved directly to the SD card, it is not saved in the unit's memory to be "downloaded" to the SD card. When a snapshot is done, it also creates a waypoint with a S prefix and a camera icon is assigned. If the snapshot is kept on the card and that card remains in the unit, when the boat icon or the map curser is at that waypoint, a thumbnail size snaphots is shown on the Chart view.

[redboat]

redboat, when the Mark button is pushed with the Snaphot feature turned on, that snaphot is saved directly to the SD card, it is not saved in the unit's memory to be "downloaded" to the SD card.

You are correct - I could have explained that a little more clearly.

[redboat]

Now for the "learning" part. Hopefully some of you guys who've been using side view can comment on these.

I'm pretty certain the while spots on the left are fish, especially since my buddy and I caught several small bass on Senkos in that area.

Not as certain about this. I suspect the cloudy areas are bait fish, but I didn't see any (visibility was only about 2 feet at the time).

I'm still playing with the different frequencies, 455 KHz and 800 KHz. The submerged bridges in my first post showed up better with the lower frequency for some reason. I think the lower frequency works better in shallow water, especially further from the boat. The higher frequency shows more detail over submerged stumps in 10 feet of water or more.

Again, any comments on these would be appreciated.

[Pete-K]

Got my 987c-Si in jan of 2006, It opens up so many spots to fish different than you fished for years.

And yes these show the fish as white spots. The one below is of crappie thousands of them. We caught over 100 in 1.5 hours even 2 at a time a lot of the time.

Sunken barge at the State line of Tn and Ky on Ky lake

Log above the Dam at Pickwick hanging off a drop off.

Ball of bait fish with fish eating on them, You can see each of the bigger fish going in for the kill.

Even caught a Big Catfish on this one right side of the screen.

[Wayne P.]

The white spots are fish of some sort, you can't be sure unless you catch one or know the history of the water.

Here is a very large bass attacking a school of shad.

This is crappie and bass at a bridge support with millions of shad forming clouds in the water:

This is shad schools near a submerged road with the creek crossing removed:

This is a group of bass with their shadows on the bottom--I know they were bass since I caught two of them:

[scrutch]

Notice how Wayne is adjusting his SI Range in the different depths and circumstances. (it's the numbers in the upper left and right corners of the screen that say 60 left, and 60 right) it is telling you that the sonar is scanning out to 60 feet from the boat on each side. You MUST adjust it as you go into different depths. A good general starting point is three times the depth. Then adjust it down for a better picture of the structure as you pass closer to the structure the second time.

I like to turn on the range lines. It helps me tell how far out the structure is from the side of the boat so I can make a more accurate second pass.

One more thing...it is very important to keep your speed constant when scanning. It helps take a lot of the guesswork out of reading the sonar.

[Wayne P.]

scrutch, the SI range lines only show the distance from the transducer, it does not indicate how far horizontally something is. The actual horizontal distance is less than what is displayed and the amount of offset depends on how deep the water is because the distance is an angle measurement.

That data is available, but the Humminbird unit does not display it. You can see that data if you play back a recording with HumViewer.

It is somewhat shown when the Contour Mode is turned on, but the range line numbers are turned off in Contour Mode.

[scrutch]

Yes, that is correct. I should have elaborated a bit more. I use it as a general guideline understanding the variables involved. The shallower the water, the closer the numbers are to a horizontal measurement. I just have to "imagine the triangle" to help me get a feel for where the structure is in relation to the boat. It gets me close enough for a more accurate second pass. Thanks for clarifying that.

[redboat]

Thanks guys - I appreciate the info.

My fishing buddy I.M. HaungUp and I went to Fork yesterday to confirm the locations of some of the culverts and bridges I found on the Navionics lake map. We confirmed three, two were right where the map said they'd be, the third was about 30 feet off.

Also saw several schools of fish of some kind - the white spots - in the stumps but as as Wayne noted it was impossible to tell what kind of fish they were and we didn't catch any. Only stayed out from about 1 PM to 3:30, was drizzly and cold.

Any suggestions for the different side view frequencies? When do you use one or the other?

[Wayne P.]

Thanks guys - I appreciate the info. My fishing buddy I.M. HaungUp and I went to Fork yesterday to confirm the locations of some of the culverts and bridges I found on the Navionics lake map. We confirmed three, two were right where the map said they'd be, the third was about 30 feet off. Also saw several schools of fish of some kind - the white spots - in the stumps but as as Wayne noted it was impossible to tell what kind of fish they were and we didn't catch any. Only stayed out from about 1 PM to 3:30, was drizzly and cold. Any suggestions for the different side view frequencies? When do you use one or the other?

At Fork, those concentrations of white spots could be crappie or sand bass. Sometimes you can tell the difference between the two by using DI, the crappie's body is wider from top to bottom. Use the DI zoom for a better look.

I use 455 kHz for Imaging because of the horizontal coverage from the water surface to past vertical. The 800 kHz has less coverage ( check the units specs.) and less depth capability. I turn on the 800 kHz occasionally to check some close returns, but that is very rare. With sonar, the higher the frequency, the less depth capabilty you have. That is why 50 kHz or lower is used for real deep water.

This is the Rt.515 bridge up from Lake Fork Marina that a friend of mine did with his Lowrance SS equipment when he first got it. He was checking out the overlay feature of 2D/DS

[scrutch]

Like Wayne I rarely use 800 KHz. I have sometimes used it for looking under docks, but even then it's a challenge. HB's 800 KHz isn't quite there yet. I think it still needs some tweaking. For me it's 455 KHz 99 percent of the time.

[loodkop]

Does the different colors make a difference in identifying structure/fish? Up to now I have been running my unit in manual but really want get away from the banks in the coming year.

[Wayne P.]

Does the different colors make a difference in identifying structure/fish? Up to now I have been running my unit in manual but really want get away from the banks in the coming year.

Yes, in most cases. I use the Inverse SI color for showing fish most of the time. Brown is the second best for my eyes. Also set the Enhance Sharpness to Low or Medium to highlight the fish. With any of the colors, the Sharpness setting is the one to makes fish really stand out from the background.

[loodkop]

Wayne, thanks I will play around tomorrow and see how it goes.

[scrutch]

The last color on the palette is a goofy green and red. I've never tried it, but I have been told by an expert that it's good for locating mussell beds.

I'm gonna try the inverse for locating fish. You think it's the best for that Wayne?

[Wayne P.]

The last color on the palette is a goofy green and red. I've never tried it, but I have been told by an expert that it's good for locating mussell beds. I'm gonna try the inverse for locating fish. You think it's the best for that Wayne?

The Red/Green pallet was developed for the glacial waters like the Great Lakes. It makes finding hard to soft bottom areas easy (that is about the only "structure" that concentrates the fish) and is being used to quickly locate the shell beds on river systems (especially the Tennesse River).

Yes, the Inverse color shows the fish the best for my eyes. Your results may vary. Use the Enhance Sharpness setting of Low or Med.

[scrutch]

Here's a little something to help you figure out what you're looking at on your HB Side Imaging screen. This was produced by Tom Vickers from Humminbird before Down Scan was introduced.