Fish Finder Training – Screenshots & Interpretations

[Feathers and Fins]

yes it is, it is the irregular bouncing marks on the bottom

[bfishn]

Not meaning to take off subject, but would you say that a black and white camera would be enough to gain insight to as what a person is seeing on the sonar? Aside from the fact that color would be nicer. Maybe a max depth that the b/w would work in versus color?

Absolutely. All other things equal (screen resolution & light sensitivity) B&W will view as good at depths as color. Once you get below 5-10 feet, it's all pretty much contrast anyway, with color being green & white instead of black & white.

[Phil Lilley]

I like this... I've pinned it for now. May do something else with it in time. May be a better place for it.

Thanks!

[J-Doc]

Thanks Phil.

I know that what I have learned within the last year alone has changed the way I fish and for the better. If only there had been a place to read something briefly or someone to explain what I was seeing on my graph years ago. It could have leaped-forward my understanding.

I hope this thread helps teach others and offers a useful resource for a long time. When members post a photo and ask "what is this I'm seeing on my graph and how do you know that?". .. that's a big value and rare in other forums.

[Feathers and Fins]

Care to share the math for everyone? :-)

I will try but formulas I haven't done since the kids needed them

If you know the size of a given object ( in this case the weight ) You can blow up the screen shot and large enough and measure it then compare that to the fish.

Egg sinker = 1 inch.... fish girth = 8inch

Now if you know the speed of the Unit plus water speed you can determine how many feet of water is covered and translate that back to length of the fish based on size of weight plus speed of boat and distance covered.

Its very much like trolling and knowing exactly where on the screen the your bait will impact a target.

[J-Doc]

Based on some quick Googling for "estimation of fish size"....

I'd say I need at least the following:

- a crash-course if not special training in marine biology and marine management

- a crash course in hydroaccoustic technology

- a Didson Sonar (mega-bucks)

- and a general understand how to calculate fish sizes based on scientific data to get within any accuracy

For now...........I'm just going to generically say "Oh that's at least a 6-pound bass".....or "Oh that's at least a 20lb striper" just to make me feel good. LOL!

http://www.adfg.alaska.gov/FedAidPDFs/fds07-44.pdf

http://yukonriverpanel.com/salmon/wp-content/uploads/2011/04/cre-16-10-klondike-river-sonar-final-report.pdf

I'm moving on for this request as it just went over my head faster than a gizzard shad fleeing a striper.

[nathanhooper]

I agree Doc, determining fish size other than maybe depth of fish is something with so many variables that it would require more time than it would to just try and catch the darn thing.

Went out last night with the wife. Tried a new area, and recorded most of the trip. Here are a few shots for interpretation. Did not catch anything, so no way to determine exactly what we saw, but I have a pretty good idea on some. Did get the wife to thinking about a camera though...

These will start from when we got out to dark. You can see the thermocline getting more evident as the evening goes on. Very interesting how it does that. I was down lining live bait, and a tried some free lining also but wind and waves was too much to tell anything from that. My wife jigged some also so I'll include some pictures of that.

Latter two are after dark. Notice the double echo on some of those also.

[J-Doc]

In the first pic, I see some large schools of bait. In the pics below that, I see a mix of what are probably white bass (the thin long arches). Any arches that have any thickness to them and long are probably striper or paddle fish (more than likely stripers). I can see your bait (continuous horizontal line) and fluctuation of the bait. I can also see where your wife was jigging (line jumping up and down. Also in the last few pics, I see what look like possibly a few walleye on the bottom (thin arch with distinct or heavily curved arch vs. flat arch). Could be bass but I'm thinking walleye. The very last pic looks like bass to me (short fat arch)

Looks like you have your chart speed about 50%? Try speeding up your chart speed to 75% and your arches will shorten up a bit and your images will get a bit crisper with less noise on the surface. Also try turning up your surface clarity. That may get you crisper fish arches. On the downside, you won't see your bait as distinctly.

[nathanhooper]

In the first pic, I see some large schools of bait. In the pics below that, I see a mix of what are probably white bass (the thin long arches). Any arches that have any thickness to them and long are probably striper or paddle fish (more than likely stripers). I can see your bait (continuous horizontal line) and fluctuation of the bait. I can also see where your wife was jigging (line jumping up and down. Also in the last few pics, I see what look like possibly a few walleye on the bottom (thin arch with distinct or heavily curved arch vs. flat arch). Could be bass but I'm thinking walleye. The very last pic looks like bass to me (short fat arch)

Looks like you have your chart speed about 50%? Try speeding up your chart speed to 75% and your arches will shorten up a bit and your images will get a bit crisper with less noise on the surface. Also try turning up your surface clarity. That may get you crisper fish arches. On the downside, you won't see your bait as distinctly.

Oh yea, you want to talk about large bait balls. We passed over one before I had started recording that was showing up 15' thick on the sonar.

I am almost tempted to run some small pony head jigs, kind of like a spider rig for crappie, to see if I cannot pickup some of those smaller fish and stuff.

I think your right though. I think that those are smaller fish of the bass variety. Where I was fishing I doubt there were paddlefish around.

On that SonarViewer from lowrance you can pause the screen and then put your cursor at different places. Those bottom two photo's, when measured, the arches are around 12" thick. Being in close to 70' of water, almost right off the main channel, I am really thinking stripers. I was cruising around 2-2.5 mph at this point trolling.

Sonar speed is actually full bore. I like a fast update. But as soon as I turn on recording it slows it down tremendously. If anyone wants these charts I have recorded I'll send it to them. The SonarViewer is a free download. People may find other pictures they have seen before and want to know. With the viewer you can also set it to greyscale for those who do not have color units.

I guess Lowrance just records raw data to the SD card and then the SonarViewer is like a unit head just like on the boat. Very interesting. Its not like screen shots. You can manipulate color and sensitivity even.

[J-Doc]

PM me and send me one. I'll take a look at it. Sounds interesting.

See........we've all learned a lot just from your interaction here. Thank you for sharing!