Are you asking where the depth finder is actually reading the depth at?

Tips: The screen shows the history of what’s been directly under the boat not a scan of everything around the boat so fishing for the specific fish you saw in the screen is not usually the play, that kinda thing is more for forward facing sonar. However, seeing fish is an obviously good sign, even if it’s baitfish it means bigger fish are probably stalking close by.

Keep in mind that unless you are trolling or floating, your prop is going to scare a majority of the fish you saw on the screen away but if they’re staging there they usually return somewhat quickly.

Most fish will not appear on your electronics because most fish tend to live on the bottom or hide around cover and structure. Your electronics can pick out cover and structure to give you a better idea of what’s below you to find these spots, so even if you don’t see fish, it doesn’t mean they’re not there.

Best practice: use a mapping service in conjunction with the habits and behaviors of the fish your targeting to break down your body of water and reduce your fishing area to several high percentage spots before you even get out onto the water.

When you do get out there, use your main prop to cover distance but switch to your trolling motor when you get close to an outlined spot. You can mark stuff on your electronics along the way for later use. When you are close to an outlined spot, use your electronics to find underwater structure, vegetation, ledges and slopes in elevation, as well as other features. If you can find juicy features around the areas you outline off water you have maximized your fishing chances.

Spend some time at each spot, if you use lures try a few and see if you can get any to bite. Depending on how many spots you want to hit try to have a set time spent at each place if you’re not having luck. General rule of thumb is don’t leave fish to find fish. So if you are getting bit, spend extra time to break that area down more thoroughly until the bite dies off, then move.

Additional: look up your manual and maybe find a few videos of your exact model so you can maximize its potential. They usually give you a detailed breakdown of what things look like and how to mark spots and set paths. Also, Depending on which transducer you got you may be able to turn on features like side scan and down scan that can make your experience even more efficient.

What model is that? I ask because it is much easier to verify with down imaging. You typically wouldn’t have a side by side with both on 2d sonar. Either use DI or mapping on the other side (or sidescan if you have that).

Yes the arches are fish.

Gahlee Moses, somebody get a net!

Search YouTube. There are tons of great videos on how to use and better understand what you’re seeing on the fishfinder. Shout out for “ 1cast 1fish” channel . He did a whole series and I found them very helpful.

IIRC the far right side is your most current depth reading below the boat, as it trails left on the screen thats whats behind the boat now

This assumes you’re going forward and have the transducer pointed straight down

What you see on the screen is where you were. What happens on the very right edge is what is happening at the moment.

So you had just passed over a spot that went from deeper than 40' to about 27' and are currently at about 35'. How steep the angle is on the screen is entirely dependent on the speed you were going at the time. Going slower results in a slower (shallower) change in depth and going faster results in a faster (steeper) change in depth.

I've got the same unit! Look on YouTube there some fantastic tutorials

big ol pile of something below you, assuming transducer points downward

If your transducer is pointed straight down, then yes, you are looking directly below you.

The graph on the x-axis is time, and each reading on the y-axis is the depth at that point in time. Or in other words, the depth below you when your boat was at that spot.

There are lots of good videos on YouTube about how to read fish finders, and in particular the Garmim Striker 4 which you have. I’d suggest watching some of those.

Clear vu, range auto brightness auto med Freq chirp 455 No zoom Scroll auto Color amber Noise reject low Surface noise hide Transducer GT 20 Bottom Search auto

I have the ducer forward of where I paddle and off the right side of the boat on a switch blade mount. It works really well and keeps it in undisturbed water

i guess it depends whats in the water. I have a striker 4 and have many experiences like that yes. maybe little bits of aquatic vegetation? need more context

https://preview.redd.it/xn45xcy601xe1.png?width=1080&format=png&auto=webp&s=5d2753a11c9bbe318278acb3981bf7f62e704279

Striker 4 xmas tree laying on bottom bait fish to the left crappie suspended over the tree. Hope this helps

I fish new waters all the time, and when I’m kayaking with a max speed of like 3.5 mph I prefer to know I’m fishing where fish are. I use side imaging mostly. Pretty awesome tech

I get this sometimes on mine, it usually lines up with when the lake turns over and the muck on the bottom floats around.

You don't need it but I can tell you that once I added it I found deep water structure on a lake I fished for years that I never knew was there. These stumps all held big fish and tons of crappie.

If you turn down the sensitivity you will see less of this. It may be small suspended bits, it may be small baitfish. It may be turbulence since you mostly see it when you are moving.

I'm not sure why your image is so wavy. They might be fish but even the bottom of the lake looks as wavy as the fish. Typically on my striker 4 fish are shown as pronounced arches. Turn those fish symbols off like the others said.

EDIT: after looking at the pictures again those wavy lines above the bottom are the same shape as the bottom, I think you may be having a technical problem.

Yes, those most likely are fish.

I think the wavy bottom/fish marks are because of the boat shifting and rocking.

They sure are. All 3 pictures show fish. Keep those fish ID icons off - they will only confuse you.

I don't have a Striker but in general I have never had luck with fish symbols. What you are looking at are probably very small and not catchable fish. The fish symbols do nothing but make one frustrated. Practice using the Striker with the fish symbols turned off and over time you will learn what larger catchable fish look like in the waters you fish.

Sorry for commenting 6 days later, but I don't think you got a satisfactory answer.

The answer is: it depends. As your transducer is sending it's signal (or ping) it bounces off the bottom (and anything else it hits) and returns back to transducer. It does this very quickly and frequently. Think of a machine gun, only an even faster rate of fire. 

Your screen scrolls from the right to the left. The screen "draws" or displays a 2-dimensonal interpretation of whatever the transducer's signal reflects off of. Your transducer continuously is sending its signal, and your screen is continuously scrolling from right to left drawing/displaying new data from transducer.

Whether or not what you're looking at is behind you or not, strictly depends on if you are moving. You can anchor, be completely motionless, and your transducer will keep sending its signal to the same spot on the bottom and your screen will keep displaying the same returns from transducer - and as your screen scrolls, it would ultimately look identical to your pic, as it keeps drawing the same bottom returns from transducer. In this scenario, what you would be looking at is directly underneath your transducer. Your screen only draws what the transducer "tells" it to. 

If you're moving (in a straight line, theoretically) your screen will be drawing and displaying what you just were over top of, and scroll to the left of screen. Assuming you are moving at a consistent speed, the far left of screen would be from the furthest away and the far right of screen is the freshest/closest data your transducer scanned. 

Your pic shows you're moving at 0.4mph. Not quite stationary, but your transducer didn't move over a far distance of bottom to "draw" what's on your screen. 

Turn off the fish ID, it doesn't work on any unit.

Everything you are reading is behind you

Learn how to read it.

99% of people use them as a track ornament. "Depth and water temp" seems to be the excuse they still plug it in. Those are almost the last two things a graph will tell me that I care about.

Within the features that unit has, I'm looking at bottom composition, structure, and big depth changes.

Watch a bunch of videos on how to read sonar, and take it out for a day or two with no rods, no tackle. Just learn how to interpret what it's telling you

Just because you have fish symbols on.. Doesn't mean you are seeing fish.

I use this for a very minimalist setup and just use navionics on my phone for mapping. Perfect for catfishing

Learn how to manually record quick contours for high resolution terrain mapping

It’s a solid fishfinder for the price. I would google search for in-depth instructions on how to use fishfinders in general. There are some good sites that explain everything very well. If you mount the transceiver to a trolling motor, you can switch between different vessels as well.

Good luck out there!

See all those arches - they're the fish you can't catch :-)

What you are looking at in those images is traditional sonar LHS and Downvu RHS. Traditional is a cone shaped beam. Downvu is a thin "slice" - usually higher frequency (and resolution/crispness) depending on your settings. Also less penetration in deeper water and narrower coverage. They each tell you different things, kind of.

Photo 2 is a bait school sitting on the bottom

Image 3 is fish moving around under the boat, why they appear longer in 2D.

Ryan Moody Sounder Skills 1 & 2

The first course is on special for $20. Well worth it imho

Something in the water is reflecting those sound signals from your sonar. Try adjusting your gain.

This is a fundamental problem with a castable sonar. First, your gain is way too high. Second, since it is just sitting still, it can literally be anything sonar detects. It could be fish. Or individual leaves of a weed, or a couple trigs coming off a downed branch.

Big school of 10 pound bass

Likely just surface noise

100 gar