Topic: Looking for thermocline screen shots?? (Read 1723 times)

Bassinkorea · « **on:** July 27, 2012, 10:38:31 PM »

Does anyone here have any screen shots of the thermocline?

I am using HDS units, so I would love to see other's HDS thermocline screen shots to help me understand what to look for.

bassn1 · « **Reply #1 on:** July 28, 2012, 06:34:25 AM »

Great question! Hope someone will be able to comply. I have been trying to understand how to read the thermocline as well. With the limited time I have on the water, Pics would certainly speed up the learning curve.

Wayne P. · « **Reply #2 on:** July 28, 2012, 07:34:48 AM »

I have several thermocline screen shots, BUT I have Humminbird equipment.

Todd Driscoll · « **Reply #3 on:** July 28, 2012, 08:19:36 AM »

Here is one from 2D sonar, thermocline at 26 feet. I don't have any shots saved from StructureScan, but as you might expect, it is much clearer and more apparent from StructureScan.

bassn1 · « **Reply #4 on:** July 28, 2012, 11:54:32 AM »

Quote from: Wayne P. on July 28, 2012, 07:34:48 AM

I have several thermocline screen shots, BUT I have Humminbird equipment.

That's what I own. HB 788 CiHDDi. So don't let that stop you from posting them.

Bigwrench · « **Reply #5 on:** July 28, 2012, 12:14:54 PM »

I've been playing around with the thermocline imaging too , I'll look through mine and if I don't have any saved I'll get some next weekend , will be a good project for all of us to learn together . Unfortunately I have set aside this weekend to try and catch up ! 3 broken down company vehicles , a wood shop that needs cleaning and shingles , a fiberglass Jon Boat needs restoring , 4 20" Chevy wheels need stripped, blasted and buffed, deck pressure washed and sealed, my garage is piled up with car parts, toys and tools ......CALGON. Take me away !

Bass Fishin & Banjer Pickin !

Wayne P. · « **Reply #6 on:** July 28, 2012, 01:27:54 PM »

Quote from: bassn1 on July 28, 2012, 11:54:32 AM

That's what I own. HB 788 CiHDDi. So don't let that stop you from posting them.

OK, I didn't want to post stuff that didn't apply to the equipment asked about.
The Humminbirds will show the thermocline with no adjustments from the Default settings. If you want to reduce the amount of the returns to just show the transition layer, you can reduce the Sensitivity setting. These are from 3 different units:

Wayne P. · « **Reply #7 on:** July 28, 2012, 01:48:42 PM »

bassn1 · « **Reply #8 on:** July 28, 2012, 02:56:55 PM »

OK./ I am at a loss to find the thermocline in any of these. Someone please

Bobby Saffel · « **Reply #9 on:** July 28, 2012, 03:02:30 PM »

Quote from: Wayne P. on July 28, 2012, 01:48:42 PM

look at the middle and the last screen shot. the thermocline is the solid red line at about 18ft on the 2d sonar. the last screen shot is the same thing just in down scan. at about 18ft and below just look kind of hazy. that's the thermocline.

bassn1 · « **Reply #10 on:** July 28, 2012, 03:10:48 PM »

Thanks.

Thought the last DI scan haze was weeds.

Wayne P. · « **Reply #11 on:** July 28, 2012, 04:56:21 PM »

Here is one more that I didn't reduce the sensitivity from the default setting (10) like I did in the one with the sensitivity setting window:

Flyswatter · « **Reply #12 on:** July 28, 2012, 05:05:07 PM »

Wayne,

Do you have switch fire turned on?

Quote from: Wayne P. on July 28, 2012, 01:27:54 PM

OK, I didn't want to post stuff that didn't apply to the equipment asked about.
The Humminbirds will show the thermocline with no adjustments from the Default settings. If you want to reduce the amount of the returns to just show the transition layer, you can reduce the Sensitivity setting. These are from 3 different units:

bassn1 · « **Reply #13 on:** July 28, 2012, 07:23:21 PM »

So that I know for sure - In the final pic the yellow/blue is the Thermocline?

Wayne P. · « **Reply #14 on:** July 28, 2012, 07:59:46 PM »

Quote from: bassn1 on July 28, 2012, 07:23:21 PM

So that I know for sure - In the final pic the yellow/blue is the Thermocline?

Yes, the thermocline will be at that level across the whole body of water unless wind or current moves it in some areas. Some bodies of water on big rivers do not get a thermocline due to current.

Flyswatter, I only use Switchfire Clear, the units do very well without the adjustments needed with Switchfire Max. Also the second and third pictures are from the 798ci SI which has the highest screen resolution and will show the minute details better.

coldfront · « **Reply #15 on:** July 28, 2012, 09:36:26 PM »

Quote from: Bassinkorea on July 27, 2012, 10:38:31 PM

Does anyone here have any screen shots of the thermocline?

I am using HDS units, so I would love to see other's HDS thermocline screen shots to help me understand what to look for.

here's one from a couple years back on down imaging...

same area, side imaging, it's harder to see...although prop wash shows up great ..

BassmanRudy · « **Reply #16 on:** July 28, 2012, 10:09:00 PM »

Thanks for all the pics guys! I don't have the best electronics on my johnboat but now I will have a better idea of what to look for! Especially in Wayne P's photo with that ditch/old road "below" the thermocline and I would have been fishing it hard!!

Please do not use Outdoor Hub Mobile, Please find and use TapaTalk for your phone

Wayne P. · « **Reply #17 on:** July 29, 2012, 07:47:25 PM »

Here is one more showing the thermocline in 2D, DI, and SI that I took today.

coldfront · « **Reply #18 on:** July 29, 2012, 08:50:35 PM »

Quote from: Wayne P. on July 29, 2012, 07:47:25 PM

Here is one more showing the thermocline in 2D, DI, and SI that I took today.

cool!

the ability of this technology to pick up density changes.. it's easy to see 'prop turbulence' in shots...and once saw the 'spiral' from a prop run at 'idle' speed...when I was parallelling a fiend in his boat...

Bassinkorea · « **Reply #19 on:** July 29, 2012, 11:49:48 PM »

WoW, great reponses from everyone, thanks so much.

I posted this and then went fishing, when I came back online I wasn't expecting so many screen shots, so thanks again, it has made it much clearer.

I fished on the big river on Sunday and I was looking in depths of 30~40 foot, but never came across any thermoclines at all. There was "some" current, but alomst nothing as this is a dammed river, more like a very long reservoir.

The water temps were 87~94 degrees throughout the day.

coldfront · « **Reply #20 on:** July 30, 2012, 07:57:19 AM »

BinK,
I think it's easier on HDS to get a thermocline image via downscan and 'legacy' modes...side imaging works...I've seen them...but the straight down views I think are easier to determine.

Don't know that it takes much current to break up a thermocline...or more likely to prevent it from forming. Do know that wind can and does break them up quickly depending upon depth, how much surface is exposed to wind, how much wind... for instance, a 25 mile long lake I spent time on (Tuttle Creek in Kansas) is about 1-2 miles wide...but with a North/sough orientation and KS winds often over 20mph....a thermocline never has a chance to set up...

then add it's an impounded river...with current (although very slight)....

no thermocline.

bassn1 · « **Reply #21 on:** July 30, 2012, 08:18:08 AM »

Quote from: coldfront on July 30, 2012, 07:57:19 AM

BinK,
I think it's easier on HDS to get a thermocline image via downscan and 'legacy' modes...side imaging works...I've seen them...but the straight down views I think are easier to determine.

Don't know that it takes much current to break up a thermocline...or more likely to prevent it from forming. Do know that wind can and does break them up quickly depending upon depth, how much surface is exposed to wind, how much wind... for instance, a 25 mile long lake I spent time on (Tuttle Creek in Kansas) is about 1-2 miles wide...but with a North/sough orientation and KS winds often over 20mph....a thermocline never has a chance to set up...

then add it's an impounded river...with current (although very slight)....

no thermocline.

That would explain what happened to the thermocline this Sunday. 5am thermocline showed up at 15 ft. Later in the morning 10am the wind was up and the lake was choppy. No thermocline anywhere. Thought my HB was on the fritz. That's for clearing that up for me. I was planning on calling HB this morning to trouble shoot my unit. Saved me a few hours on the phone with CS.

bassn1 · « **Reply #22 on:** July 30, 2012, 08:28:52 AM »

Wonder if, since the thermocline can be broken up that easily does it affect the fish's position/depth as much as is claimed.

For example, windy all night no thermocline. 1-2 hours of calm, thermocline sets up. Back to windy again no thermocline. If this is the case, then the fish will have no time to adjust to the varying O2 levels. If the thermocline were set up for a few days then I can see where the fish will have time to adjust. Adds a lot of new factors to the movement of the fish. $:-\$

coldfront · « **Reply #23 on:** July 30, 2012, 08:53:34 AM »

Quote from: bassn1 on July 30, 2012, 08:28:52 AM

Wonder if, since the thermocline can be broken up that easily does it affect the fish's position/depth as much as is claimed. For example, windy all night no thermocline. 1-2 hours of calm, thermocline sets up. Back to windy again no thermocline. If this is the case, then the fish will have no time to adjust to the varying O2 levels. If the thermocline were set up for a few days then I can see where the fish will have time to adjust. Adds a lot of new factors to the movement of the fish. $:-\$

think so...when a 'strong' thermocline sets up...if there is enough organic material (dead) below that thermocline, it can have lower oxygen levels... in my opinion, if O2 levels are acceptable fish will go to the thermocline and below as a 'thermal refuge' ... if o2 levels diminish due to decay (anaerobic process - consumes O2) then they'll stay typically on top of the thermocline where O2 levels are maximized and temps are minimized...but you can't overlook the need to be close to feeding opportunities...

one other thing I'll toss out regarding your observation of a 'dissapearing' thermocline. there are organisms in the water (daphnia spp., chironomids, etc) that typically reside on the bottom of a lake...these organisms will ascend up throught he water column in a typically di-urnal pattern (twice)...usually overnight... I think that early morning sonar reads can pick up these daily movements and show you what looks like a return line...and would assume it's a thermocline...

normaly a thermocline would not be expected to break down just because of 'time of day'...and I'd suggest the possibility, particularly early in the morning, where you're seeing the remnants of this vertical migration as it settles back...

through the years, many things I've seen...one thing I've gotten really comfortable with: if the sonar 'shows' it, it is there.

'what' it is may not be entirely clear...but something is there...that is based on water density change and drives the sonar return signal...

Wayne P. · « **Reply #24 on:** July 30, 2012, 10:19:22 AM »

Quote from: coldfront on July 30, 2012, 08:53:34 AM

think so...when a 'strong' thermocline sets up...if there is enough organic material (dead) below that thermocline, it can have lower oxygen levels... in my opinion, if O2 levels are acceptable fish will go to the thermocline and below as a 'thermal refuge' ... if o2 levels diminish due to decay (anaerobic process - consumes O2) then they'll stay typically on top of the thermocline where O2 levels are maximized and temps are minimized...but you can't overlook the need to be close to feeding opportunities...

one other thing I'll toss out regarding your observation of a 'dissapearing' thermocline. there are organisms in the water (daphnia spp., chironomids, etc) that typically reside on the bottom of a lake...these organisms will ascend up throught he water column in a typically di-urnal pattern (twice)...usually overnight... I think that early morning sonar reads can pick up these daily movements and show you what looks like a return line...and would assume it's a thermocline...

normaly a thermocline would not be expected to break down just because of 'time of day'...and I'd suggest the possibility, particularly early in the morning, where you're seeing the remnants of this vertical migration as it settles back...

through the years, many things I've seen...one thing I've gotten really comfortable with: if the sonar 'shows' it, it is there.

'what' it is may not be entirely clear...but something is there...that is based on water density change and drives the sonar return signal...

It is called plankton and an isolated column looks like this, and may be so thick that the sonar interprets it as the bottom:

News:

Author Topic: Looking for thermocline screen shots?? (Read 1723 times)