How To Read A Fishfinder

[BigTerp]

Now that waterfowl season is over and I get to use my sonar for more than just bottom depths, I need a good lesson on how to read it. I have a basic Lowrance X-4, black and white, nothing fancy. Not sure what I'm looking at in terms of bottom. Is it hard? soft? Is that hump a rock? a log? What settings should I mess with? How do I even know I have it setup properly? Anything and everything you can tell me to help me properly read this thing is appreciated!!

 

[DrNip]

YouTube.

 

[onthewater102]

Definitely you tube that question

 

[DrNip]

Tons of good videos there.

 

[Bigwrench]

I have been in the learning curve for awhile now and if there are any specific questions I can try to help you out . As the guys mentioned YouTube is a great resource , particularly search for Jason Gilstrap with Get A Limit outdoors. He has seriously helped me on mine. Basic setup procedures , advanced settings , drop shotting Etc. I have been using Lowrance/Eagle units back to 1990 . I currently have 2 HDS8 Gen 2's with LSS, Sonic Hub and NMEA 2K , Elite 4X. I have had the LMS350A, HDS5 & HDS 7 Gen 1 units and just got the eagle Magnaview with this Tin Project as well. Paul Mueller has some great videos as well as Todd Driscoll.
I can tell you , don't use the Fish ID feature , learn to use the arches. Turning Fish ID on has a tendency to dumb down the unit. In most cases for freshwater shallow (60' or less) the factory presets and auto function work just fine.
As far as the bottom returns and what your seeing try taking a look at Lowrance's website they have a Sonar Tutorial that explains a lot of the basic stuff
https://support.lowrance.com/system/selfservice.controller?CONFIGURATION=1001&PARTITION_ID=1&secureFlag=false&TIMEZONE_OFFSET=&CMD=VIEW_ARTICLE&ARTICLE_ID=2967
Hope this helps.

 

[2sac]

The stronger the return, the closer to the boat. The darker the shading the stronger the return meaning the fish are under the boat. The lighter the shading means the fish are off to the sides or further away from the boat. As far as bottom composition, a hard thin black line is a hard bottom. The thicker the line, the softer the bottom. Weeds and grass will appear differently but you should be able to tell their relation to the bottom. The cone spreads out further the deeper the water. The diameter of the bottom of the cone could equal the depth of the water ie. 15fow=15ft diameter or could equal up to 50% of the depth ie 15fow=7.5ft diameter. It depends on the unit specs.

 

[user 13737]

https://www.jasonhalfenoutdoors.com/ great info here, even if it is mostly HB SI related a lot of the info on the page teaches you to read 2d as well

 

[BigTerp]

2sac » Yesterday, 6:58 pm[/url]"]The stronger the return, the closer to the boat. The darker the shading the stronger the return meaning the fish are under the boat. The lighter the shading means the fish are off to the sides or further away from the boat. As far as bottom composition, a hard thin black line is a hard bottom. The thicker the line, the softer the bottom. Weeds and grass will appear differently but you should be able to tell their relation to the bottom. The cone spreads out further the deeper the water. The diameter of the bottom of the cone could equal the depth of the water ie. 15fow=15ft diameter or could equal up to 50% of the depth ie 15fow=7.5ft diameter. It depends on the unit specs.

Thanks everyone. Bigwrenche's Lowrance link was especially helpfull. But I'm a bit confused. What 2sac is saying makes sense, but Lowrance seems to say the opposite. From Bigwrench's link:

Mud, sand and vegetation on the bottom absorb and scatter the sonar signal, reducing the strength of the return echo. Rock, shale, coral and other hard objects reflect the sonar signal easily. You can see the difference on your sonar's screen. A soft bottom, such as mud, shows as a thin line across the screen. A hard bottom, such as rock, shows as a wide line on the sonar's screen.

So according to Lowrance, the first picture is a soft bottom and the second picture is a hard bottom? When they say thin/wide line they are referencing the grey line below the thin black line, correct?

Here are the images they are referencing:

 

[DrNip]

Grey

 

[muskiemike12]

Never run the unit on "Auto". It dumbs down the unit and is changing the settings constantly. You cannot make decisions on bottom content because the unit is changing the sensitivity level. Set the depth range to over twice what the deepest water you will be graphing is. So if you are looking in primarily 15-20 fow set the unit for 50. Set your sensitivity some where between 55-75%. Hard bottom will produce a distinct double echo. Hard bottom will show up as a thinner line, soft thicker. If you want a more detailed view of the bottom use your split screen zoom.

The learning curve will be shortened if you can find a buddy who knows how to run a graph properly. Take him out a few times and let him make adjustments. I'm not sure on your model, but it may not remember the custom setting you select. Some of the lower price units to not have a memory and switch to the default setting (auto) every time you power up the unit.

 

[2sac]

Here's a picture that might be easier to understand. This is off a 998 and the fish were walleye, and drum. If you look to the right of the 2d screen you see a color bar. The top of the bar(yellow) is the strongest return(this would be black on your unit) and bottom of the bar (dark purple) is the weakest return(this would be light grey on your unit) If the bottom was soft or had weeds, it would be more purple and red and less or no yellow. The DI and 2d don't match exactly because it's from an SI unit. If this was a DI unit, the 2d would match the DI.
The transducer is set on 200khz so the cone diameter equals around 1/3 of depth or 14ft
Bottom is hard rock and the yellow return tells me that. The reds and purples on the bottom are still a hard bottom, only they are at the edge of the cone. The "fuzz" is algae and I had to turn the sensitivity down on the 2d because the algae cluttered the screen. The 2 fish near the top (yellow) are directly under the boat(cone). The {red} fish near the bottom is slightly off to the side of the cone. Which side, I can't tell you. The purple fish are at the edge of the cone and they are the weakest return.

 

[BigTerp]

Thanks again. All starting to make more sense. I'll be hitting up a lake this weekend. Will give me the chance to dial in my sonar.

 

[Bigwrench]

BigTerp » 03 Apr 2014, 16:20[/url]"]Thanks again. All starting to make more sense. I'll be hitting up a lake this weekend. Will give me the chance to dial in my sonar.

That's probably the biggest factor is just playing with the settings and getting the best images out of it on the water
The more time you spend tweaking and playing around with it the more familiar you will be with what your seeing . Also if you can ever swing it a DI unit is awesome especially when you have a split screen and 2D right beside it , can really help you understand what your seeing on 2D easier. I have a Lowrance DVD somewhere if I can find it Ill send it to ya if youd like just pass it on to someone else when you don't need it anymore

 

[huntinfool]

Heck, I've only ever used my unit for depth.
I guess I have a lot to learn. I'll be clicking those links after work.

 

[Bigwrench]

Heres another good read on sonar.
https://doctorsonar.myshopify.com/b.../12380345-lowrance-pros-corner-by-luke-morris

 

[BigTerp]

Was able to mess with it a good bit yesterday when I had my boat out. The lake we were on had alot of vegetation in it, so it made things a bit difficult at times with interference on teh screen. But I did get things dialed in fairly well, and got alot better understanding of my unit. One question I had is my unit has a grayline setting. It goes from 0-100%. What does this do and what should it be set at?

 

[DrNip]

Bigwrench » 06 Apr 2014, 20:25[/url]"]Heres another good read on sonar.
https://doctorsonar.myshopify.com/b.../12380345-lowrance-pros-corner-by-luke-morris

Very good read.