When scanning the lake bottom with your Side Image unit regardless of what brand or model you have to get the best images requires the correct angle you scan from. In the images below I have images of a side scan with a Humminbird unit at different angles to show you what I mean.
In the image above the boat is on the right side of my boat and I’m heading up river. And as you see that I almost ran over the top of the boat by looking at the top left corner of the boat with my boat.
In the image above you can see that I took my boat over the very top of the sunken boat with part of the boat on the right and the left sides of the scan. By the way can you see the Bluegill beds in the sunken boat.
In the above image you can see I got the correct angle of the sunken boat and you can see the entire boat and the details of the boat.
Look at the above image and you can see I got the angle wrong.
Here I have the boat and chart speed wrong for the best scanning image.
Now in this image you can see it all came together with the correct boat speed, correct chart speed and the correct angle. I’m on the inside shallow side of the boat scanning up river at a slight angle to the boat to get the best scan of the boat.
So the next time you are on your lake and spot something, try scanning it from different angle and speeds to get the very best image of what you are looking at. This all takes time on the water with your unitsand playing with the settings.
In an earlier blog I wrote about needing Side image to get the most out of your Down Image scanning. In this blog I’ll show you an example when you needed Down Image to find the structure that is hard to see with the Side Imaging transducer. In this scan I am using my Humminbird Onix 10 Touch SI/DI unit. Then as usual I convert the recordings using ReefMaster Sonar Viewer software. In this blog I will only be posting three images and you can see why you still need both your Side Imaging and down Imaging transducer at the same time in most cases.
In most instances I use only my Side Imaging while scanning for structure and I use my Down Imaging to try and locate fish whether it’s bass, crappie, white bass or any other species of fish i might be after on that trip. When I’m scanning for structure with my Side Image I usually have my unit scanning out to 100 feet on each side. If I’m looking for fish with my Side Image and Down Image together I set the Side image range to either 50 or 60 feet. On my Side image I use the 455 kHz and on the Down Image I set it up to use the 800 kHz settings. This will usually give me the clearest images i have found on my units.
The color palette will be a matter of personal preference. On my Onix for example before all the software updates I liked to use the “Green” palette but with the last software update I find myself using the #2 “Amber” palette the most. On my 360 transducer in shallow water I like the “Gray” palette the best. As usual you will have the continually make changes on the fly with your “Sensitivity” and your “Contrast” setting during the scanning process.
Okay now for my first image from a recent scan I did on the water. I,n the image below you can see a lot of stuff in the water, there are lots of schools of bait-fish. You can see some larger fish near the bottom which could be catfish or Asian Carp. You can the edge on the old creek channel bank on the right side of the image. You can see some larger fish up in the water column under the bait-fish which could be bass, stripe or crappie. You can see what looks to be a tree limb on the lower left of the image and possibly a brush top almost in the center of the screen.
Now in the next image I am using the Down Image transducer to run the exact as area, as a matter of fact I was running both the Side Image and the Down Image at the same time to get this scan. But you can now see what I missed with just the Side Image transducer.
Wow, now what do you see in the Down Image scan? You can now clearly see the three big man-made brush tops someone dropped in the lake! You can still see the bait-fish and a few fish but not everything you saw in the Side Image scan image.
And finally in this last image I’l show you them side by side and see what you can and can’t see if you were only running one without the other.
Remember I was running both at the same time over the exact same area and I would have missed the three big brush tops without having them both on at the same time. So you can clearly see you need to run both at the same time to get the most out of your units. This is one reason you need the larger units like the 10″ or 12″ for the largest screen area you can see at once. I also run a Helix 12 SI Mega but most of the time I only use it for mapping as i find my Onix unit gives me the clearest image of the both of them.
I hope you get a little more understanding out of your expense tools you have added to you boat.
I seen a post on Facebook the
other day about “Do You Really Use Your Depth Finder To Help You Catch Fish”? That
is a really good question, as I have seen a buddy that I fished with that had a
new Garmin Depth Finder on his boat but never turned it on while we were
fishing. In his case I think it was all about having the “Newest Thing” on his
boat. It’s the same as having Power Poles® on your boat but never put them
down. If you’re going to pay out the money for the newest technology then you
need to take the time to learn to use them. I personally have six units on my
boat but actually only use three or four of them at a time. Two of the units
were small in-dash depth finders that came with the boat.
One thing I had a hard time
understanding when I first got my first depth finder an old “Super Sixty”
flasher that I used to catch a lot of fish watching it. I could watch my jigging
spoon go up and down as I lifted and lowered my rod and see the fish signals
come to the spoon while watching the flasher. Now that we have the choices of
Side Imaging, Down Imaging and Sonar all in the same units they have really
become a big help in catching fish whether it be bass, crappie, bluegill or
As we ride around the lake or
body of water you are fishing looking at things that pop up on the screen and
wonder what they are. To learn this, we must both spend the time on the water
learning our units and to actually know what they are that we’re looking for.
Here is a screen shot of something on the bottom that my boat passed over. One
what is it and second where is it in relation to the boat and where do I need
to make my cast to make contact with the structure?
Okay take a look at the photo
above and see if you can tell, first what is it, and second where is it and
third where do I cast to so I can try and catch any fish that may be located in
the structure. Just by looking at the photo above, I first thought it was
directly under the boat which in this case part of it is but most is not. If it
is under the boat where under the boat is it located? I would in the past make
a cast straight behind the boat to try and make contact with the structure.
Sometimes I would make contact with the structure but most of the time I did
not. The one way we can tell that part of the structure is partially under the
boat is the red coloring in the screen shot in the brush top. This red color tells
me that the strongest signals are in the very center of the sonar cone. Take a
look at the photo below to get a better understanding of what this means.
Now let’s take a look at the same
piece of structure with our Down Image unit and see if we can see what it is
and where it is.
Okay we can tell that it looks to
be a brush top someone placed in the lake and there looks to be one fish on the
right side of the brush top on the right at the edge of the screen. By looking
at the fish and the shape it could possibly be a crappie as it is tall as it is
long. But this is only a guess and we have no way of knowing unless we actually
catch the fish.
Okay so now we know it is
possibly a brush top but where is it. Well again since I thought I drove over
the structure you’d think it is behind the boat. But again, it could be but
also could not be under and behind the boat.
Now let’s see what the structure
actually is and where it is in relationship to the boat. We can determine all
this by using our Side Image unit. Not only will it tell us what it is but
where it is located and where we need to make our cast to try and catch that
fish that we are after.
Okay from the side image view we
can tell that it is actually a brush top under the boat and also a bucket with
what looks to be canes by seeing the shadows of the canes. And last a huge
stump to the right of the boat about 20 feet to the right of the boat. By the
way can you find the fish in this screen shot? Hint look for the shadows they
give the fish away.
In this last screen shot I did with third party software available to you the angler you can see the location of the structure.
So, to get the best out of your new or current units you
have to use the tools you have and learn to use them to help you catch more
fish. After all this is the reason, we spent the hundreds of dollars if not
thousands of dollars on the “Newest Thing” for our boats.
region in a thermally
stratified body of water which separates warmer surface water from cold deep
water and in which temperature decreases rapidly with depth.
The thermocline is formed on lakes with little to no current flow that allows the mixing of the top and bottom layers of the lake waters. Since cold air and water is heavier that warm or hot air or water the heavier sinks and the warmer rises. In the following three images you can clear see the thermocline. Summer and early fall is the times that the thermocline is most prevalent with the high air temperatures this time of the year.
Why knowing where the thermocline is important to you as a fisherman? Simple it will define the maximum depth you need to be fishing. The thermocline is void of life giving oxygen so the fish you are seeking can not live in the thermocline. During the summer and early fall, adjust your unit to see the thermocline. Scan the area you are planning to fish and look for the top of the thermocline. Let’s say the top is at 27 feet as in the images in this blog. Then the maximum depth you need to fish is no deeper that 27 feet. Look for a or drop-off, shell mound or hump that is shallower than 27 feet and fish there if you see fish on them with your down image units.
the thermocline is easy with the new Side Image and Down Image sonar units, in
my case I use the Humminbird Onix 10 SI and the Helix 12 Gen2 Mega Scan. You
will need to learn to adjust the sensitivity and contrast settings. You can
find settings on this blog just do a search in the search bar. There are a lot
of YouTube videos on how to tune your units.
Hope you find this blog helpful in understanding the thermocline in your fishing.
When Wilson Lake was impounded there was a lot of old structures, canal, bridges and other structure let on the lake floor. With the advent of the new sonar technology such as Side Imaging and Down Imaging you can still find a lot of them.
I have both Humminbird Onix and Helix Mega Scan units on my boat. These amazing pieces of technology enable me to see what’s still laying on the ;lake floor to this day almost a 100 years later!
A Little History on the Lake
Wilson Dam spans the Tennessee River between Florence (north) and Muscle Shoals (south), Alabama. It stands at an elevation of 508 feet and crosses the Tennessee on a 20-foot roadway along the top of the dam. Impoundment of the Tennessee River above Wilson Dam has created Wilson Lake, with a maximum width of 1.6 miles and a main shoreline of 154 miles.
Wilson Dam was erected by the Army Corps of Engineers in 1918-25 and turned over to the Tennessee Valley Authority when that agency was established in 1933. Wilson is a concrete gravity-dam on a blue limestone rock foundation. The total length of the structure is 4,535 feet, the height 137 feet, and the maximum width at the base (Including the apron) is 160 feet. The head the water depth on the upper side of the dam is 97.6 feet. There were originally 58 spillway gates in the face of the dam, each capable of discharging 10,000 cubic feet of water per second.
As I scan the lake bottom with my Side Image and Down Image units I’m always looking for objects that are on the lake bottom. If I do manage to find something, if I can I’ll research and see if I can find out what it is and if possible try to find a photo of what the object is or was. In the two photos below I found an old submerged arched bridge crossing a small stream or creek bed. You can clearly see the creek bed in the Side Image photo.
Click on the photo thumbnails to get a larger view.
I found an old submerged mill a couple of years ago that an old time fisherman told me if I had ever looked for it. In the two photos below you can see what the mill looked like before it was torn down and all that was left was the stone work of the mill.
The following photo is an old marina boat cover slips that instead of being torn down was easier to just pull it out into the lake and sink it. The tin metal top and sides are still on the old boat cover slips. I have tried to find a photo of the original one but have not been able to do so.
In this blog I’ll be discussing Side Imaging Sonar and Down Imaging and do you need it. As I discussed in my earlier blog on Sonar versus Down Imaging was it really needed. From the images I’ll post below we can see that some of the structure is visible in the Sonar and the Down Image views but the problem is where they are located in relation to the boat.
As stated in the earlier blog I will be converting recordings done with my Humminbird Onix 10 SI Touch and my Helix 12 Gen 2 Mega Scan SI units. The software I use to view the recording is ReefMaster Viewer and sometime I will use Deepview FV as well as AutoChart Pro. Three of these are purchased software and the other one is a free software version. You can do a Google search to find out more on these products. As for recording with your Humminbird unit I have a blog discussing this as well just follow this link “Recording”.
The problem with Sonar and Down Imaging while fishing or even scanning the lake bottom with your units. Is to determine where the structure is in relation to your boat. Since we are dealing with a 2 dimensional flat screen and scanning a 3 dimensional world. Since the software on the units is only placing pixel dots on the screen there is no way to show the bottom in a real world display. That is unless we are using Side Imaging.
With Sonar and Down Imaging as we drive over the structure is it under the boat as the display shows? It possibly could be and we can tell this with the Sonar view by looking at the colors displayed on the screen palette. Since on a Sonar transducer set to 200 kHz the cone angle is pointing straight down and for an example shining like a flashlight beam. Take a flashlight and turn it on and point it straight down at the floor. The circle of light you see will represent the transducers cone angle. As you can see the angle is in a circular pattern and any object that enters the cone will be visible. Now lower the flashlight down towards the floor and you will see the circle of light gets smaller. This represents the depth of the water your boat is setting in. With a standard 200 kHz transducer the circle will be 1/3 of the depth of the water, for example in nine feet of water you will only be scanning a three foot circle of the bottom. Now move out into 30 feet of water and now you will be looking at a ten foot circle of the bottom.
With all that being said if your boat is in 9 feet of water and you drive your boat over say a stump, and it shows up on the display screen then that stump is directly under the boat. That is under the transducer where ever it is located.
Now let’s say we dropped a waypoint on that stump and wanted to fish it. As we turn the boat around and go back to the waypoint where is the stump in relation to the boat. Again on the display as we get closer to it it will show up on the display but now is it under the boat or in front, rear or right or left of the boat?
The only true way to know for sure is either with the Side Image or the Humminbird 360* transducer. With the Side Image transducer the problem is we now have to drive past the stump to see it displayed on the unit. But now we will know if the stump is on the right side or the left side of the boat. With the Humminbird 360* transducer we can see the stump without having to even move the boat. If the stump is at a three o’clock position we just cast to the stump at a 90* angle to find the stump.
I hope this explains a little the advantage of the Side Image transducer. Take a look at the images below to see what I am trying to explain. I’ll do a blog on the Humminbird 360* transducer after I get on the water and do some screen shots with it.
Click on the Thumbnails for an Enlarged view of the images.
In this image we can see a stump displayed on the Sonar but only know it is located slightly to the right of the boat by looking at the Side Image view.In this view we see the top is directly under the boat and slightly behind the boat.
In this image there is a creek channel that the boat just passed over but but it did not show up on the Down Image view.
Now let’s look at this gravel point that is off the the right side of the boat. Without the Side Image view we would not even know it was there.Can you see the gravel bar on both sides of the boat in the Down Image view. See the tree top slightly to the left side but still under the boat?Stump field to the right and a stake-bed to the left not visible on the Down Image view.
Stump field to the right and a stake-bed to the left not visible on the Down Image view.
I get asked sometimes if Down Image is really worth the extra expense over the regular Sonar units. I definitely have to say yes but only if you do not know what your looking at with the Sonar unit. I’ve used sonar units since the old flashers and paper graphs from back in the mid to late seventies. One thing for sure is that you want to get one with a GPS so you can return to the structure that you will find with them.
My units are Humminbird Onix 10 SI Touch and Helix 10 DI and a Helix 12 SI. All of these unit have GPS and Sonar built into them. I’ve also used a Garmin unit and Lowrance units with good results.
One thing I must say is that of all the Humminbird units that I have owned, everyone of them has had software issues and several have had to be returned to Humminbird for repairs! I don’t know why they can not get their software right before they release their products. Anytime that they have to release five to ten software updates that tells me they have issue with their software!
All of the images you will see in this article will be from recordings that I have recorded with either my Humminbird Onix or my Helix 12 units and then viewed in ReefMaster Viewer software.
I use the Sonar with the 83/200 kHz transducer settings and my chart speed is normally around 5 or 6 with my boat speed at about 3.5 to 4 mph when I’m doing the recordings.
Look at the images below and you will be able after a lot of time on the water looking at different structures to learn what you are really looking at. In my next blog I’ll show you the Side Images and the Down Images views.
Hope this helps you to learn your units a little better and catch a few more fish.
Click on the image thumbnails for a larger view of the images.
In this blog I’ll give you a little history about the locks at Wheeler Dam located on the Tennessee River.
This a photo of Lock #2 which is located above Wheeler Dam, which was part of the original canal system that ran from lock #1 at the mouth of First Creek all the way to the Riverton Lock at Waterloo. The above lock at the mouth of Second Creek is now under about 40’ feet of water.
Located two miles above Wheeler Dam, now submerged in about 45′ of water.
The lock is located about 50 yards out from the mouth of first Creek in about 45 feet of water. The GPS coordinates if you would like to look at it with your Side Image or Down Image units is N034.48.734 – W087.20.799.
The original lock at Wheeler Dam was started about 6 months prior to the forming of the Tennessee Valley Authority in 1933. The project was completed in 1936 and stood until the collapse in 1961.
In this photo you can see an old paddle boat going through the lock at Wheeler dam.
Collapse – June 2, 1961
History – Back in 1961 the original lock at Wheeler Dam had a structural failure. The side wall collapsed killing two people. The Corp of Engineers was in the process of constructing the new larger lift lock that is now in place. There was almost daily blasting to remove the side walls and to get down to the bedrock. Almost immediately after the failure the Corp got into high gear as all barge traffic on the Tennessee River came to a halt.In this photo you can see where the wall collapsed and you can also see where water from Wheeler Lake is rushing in through the lift gate. There was also flooding into the construction area where the Corps of Engineers were blasting for the new lift lock.
In this aerial view that was taken 5 weeks later you can see the full damage side wall collapse.
During construction some barge traffic was continued as you can see in this photo by unloading from below the dam onto barges on the up river side of the dam. This is a grain barge unloading it’s cargo of about forty five feet.
Photo of the down river view entering the new lock at Wheeler Dam, you can see the old original lock on the right after repairs.