Weed lines?

[Functional]

I keep seeing references to people finding submerged weed lines with their sidescans. Can anyone show what that would look like? I have a hard time determining if what I'm seeing are rocks or weed lines and wanted to see if anyone can point main differences aside from stopping and throwing out a jig and dragging to find out. 

[WIGuide]

They'll look different depending on what kind of grass and it's growth stage. I don't have any screen shots handy, but if you're looking to figure it out on your own, find some emergent grass and look at those edges on side scan for comparison. 

[casts_by_fly]

Here’s one example with side and down together. This is a moderate thickness weedbed and where it drops into the main lake on a ledge.

 

 

here is an example of rocks

 

 

Its tougher to see the weeds picture a little (its a zoom from a bigger picture) but its typically fuzzier and has lines running away from the boat.  Rocks tend to have more shadows and highlights behind them because in a rock field there is often another rock just behind the first.

[Functional]

I took some images the other day when I was able to get out. I'll post them up later today/tomorrow. 

 

Your DI/SI looks like its right under the boat but trying to see what it looks like when its not under the boat. Best guess I have is it makes the image in those parts looks streaky. 

[gim]

There is a very established weed line forming on many lakes here now.  I use 2D sonar more than I use side scan to find that edge, if I cannot visually see it.  Some lakes are so clear I can actually see where the weeds stop growing super thick.  I will drive around using my GPS and 2D sonar and it makes a trail where I'm driving.  I try to stay right on the edge.

 

Then I go back and move just outside of that trail to fish it, casting towards shore.  Last weekend I started dropping a neko/wacky right along that edge and caught some decent fish.

[casts_by_fly]

1 hour ago, Functional said:

I took some images the other day when I was able to get out. I'll post them up later today/tomorrow. 

 

Your DI/SI looks like its right under the boat but trying to see what it looks like when its not under the boat. Best guess I have is it makes the image in those parts looks streaky. 

 

yes, the grass was right under the boat there, but it looks the same when its off to the side The same left right streaks and general fuzziness.  Post your pictures up later and we can have a look.  I'm also going out this evening and will try to take a picture on the Helix 9 which shows the detail better.

[Functional]

Ok, the one with the bridge (first photo) I'd say is all rock/ledges. The other one I know there are weeds out to the right not more than 20-30ft poking up through the surface. I'm not quite seeing what would show weeds to the right and on the left I'd have initially thought that was rock but some of the "hard edges" are very squiggly and I've never seen rock like that.

 

Thoughts?

[casts_by_fly]

The first one looks like rocks and almost a cliff. Second picture I’m not sure. If you really wanted to know, next time you’re there mark a waypoint when you go through with side imaging and then go back over it with down imaging to see more detail. 
 

when you took the second one, we’re you in a kayak that was rocking back and forth?  The squiggly line looks like it should be one straight line but the boat was rocking left and right. I get that on my kayak a bit. 
 

here are three more from tonight. This is milfoil. Same spot in all three. the first picture was when I was cruising over top of it and just hit the end. You can see the end on DI and where the bright ends on the SI. Second picture was a little further on so that I wasn’t right on top of the grass for you. Still a fairly defined line and then lots of speckle/fuzzy behind it. The third is mega live of the same grass line. 
 

 

 

[Functional]

@casts_by_fly those images are perfect and I can understand that!  I just don't get that with mine. I KNOW for a fact there is water Stargrass to the right in the second pic because it lines just about every shore on my lake and I can visually see it come out of the water. I'll probably get out again Monday but I'll take some imaging and take a photo of what I visually see. It was recommended above I scan an area I knew had grass to see what it looked like and this is why I have issues lol. 

 

These were from a boat,  in dead calm water running about 3-4mph so no rocking. 

[casts_by_fly]

We don't have stargrass, so I just did a google image search.  Are you talking thick beds of it or open strands?  Looking at the pictures, its a pretty fine stalk and the leaves are like eelgrass.  I'm not sure how strong of a return you'll get from it if it isn't a thick tangled bed.  Knowing the grass now, there are a couple shadows in the upper right on the right picture that could be from clumps.  Also, the general darkness on the right I attributed to the water getting a little deeper and dropping off.  If that's not the case, then that might be your subtle cue that something is blocking your sonar signal.  That, combined with the thin strands could be why you're not seeing it.  Next time out, try turning up your sensitivity (and maybe down your contrast) and see if you can start making out some more detail.

[Functional]

@casts_by_fly nah I looked up images and it looked like stargrass it but its not fine. Reading descriptions and photos its more like Alligator grass or Water Willow. Very thick stalks with narrow leaves off it. Decently dense but a swim jig can get through it, sometimes a chatterbait.  I'm just using these patches to see what I'm looking for on SI with anything that might be submerged on this lake or others. 

 

I'll play with some settings monday and take some more images and some photos of the plants. 

[gim]

10 hours ago, casts_by_fly said:

the first picture was when I was cruising over top of it and just hit the end

That's very obvious to me where the weed line ends.  Those are the areas I am targeting here.  Even though I am using a Lowrance unit myself, my image looks very similar.