how to read a depth finder

[hawghunter1744]

Okay this may seem like a stupid question but I'll ask it anyways. On a depth finder like the one below, how do you read it?? For example, the picture shows the riverbed being higher on the left than on the right. I don't understand how that's oriented with my boat. If I see that on my depth finder, does that mean that it's shallow to my left and deep on my right? Or is it facing the other way (sort of like the old Mario on Nintendo) and it's shallow behind me and deep in front of me?? Also, How do you tell what's grass and what's a fish??

[Garnet]

Everthing on your screen is history, so if you went forward and left everthing you see is behind and to the right.

Garnet

[sneaker]

The picture on the screen is a history of what your boat has passed over. On the right is the bottom data of your present location, on the left is the bottom data taken earlier. The scroll speed (how fast the picture is written) can be adjusted so that it takes a 60 secs to complete the pic. Then the data on the left is what the bottom looked like one min ago. In the picture you provided the boat passed from shallow to deeper water.

Most FFs will draw a pic of a fish (fish ID option) if you passed over a fish. Some will write the depth of the fish next to the image. The side looking FFs will tell you if the fish was left or right of the boat when you passed over it.

The bottom texture is indicated by the width of the bottom displayed. In the example you provided the bottom is soft with a hard layer deeper down. If you were over a hard bottom the bottom displayed would be shown as a thinner line. Weeds look like a soft bottom, but will usually vary in depth with a harder bottomline below .

When your boat  passed from deep to shallow water, and then back to deep again, you will see a mound on the screen. This is important botom structure information that you want to pay attention to. Fish will often hold, or hang out on this kind of bottom depth change, and you will want to fish that structure.

With experience you will find the FF is one of the most valuable tools you have on the boat. Play with it and learn what things are usefull. For example the gain (or sensitivity ) will have a big effect on its ability to show fish. Too much gain and it will show fish everywhere, too little and their will be NO fish. Fiddle with it and you will learn what is real and what is junk. Good luck...

[fishfordollars]

You are in the bottom of the river.

Some things to help you:

Read the manuel

Take it off automatic

Turn the fish ID off.

Spend some time over a location you are sure of what's on the bottom

Then read it to compare

[SnowBass23]

You've already got some great advice with what Sneaker and Fishfordollars have said.  I like the idea of turning the fish id off and getting used to just fishing structure.  I am learning myself, and with my ff it has the 'dual beam' meaning it has a more direct beam directyly below the transducer and a wider beam out and around it.  The problem this gives me is that it shows 'fish' of a different color to let you know when they are in theory directly below the boat, or out and around it.  So take this information with a grain of salt.  Since I don't know for sure that the fish is on the left or right side of the boat, I use it as a guide of where the fish are located as far as depth.  

Again, get out in places that you have a good idea what is below you (clear water helps! ) and then learn how your unit displays it.

[Team9nine]

See if this helps...

-T9

[jemackinnon83]

I don't mean to but in but I think this question fits in here.  So if you've got a wide angle transducer is the depth reading still from directly under the boat?  Seems to me that a wide angle would be good for displaying fish but not so much for depth or structure.  In deep water how would you ever find a hump if it could be anywhere in the wide angle's view?  Thanks in advance.

[SnowBass23]

My transducer in particular is a dual beam.  To my understanding the primary beam is the one that is going to give the most definition of structure and objects, it is the one that will also be giving you depth readings.  The wide beam is there just to give a bigger picture of objects moving around the boat.  

On a lighter note I have had things hit the transducer before and make it point at a funny angle, so it will suddenly read 800+feet and show thousands of fish!

[outdoorsman]

Simple concept : It's a Bird's eye view of everything on the bottom and in between. It also helps to look at the land or shoreline, that also helps interpret you depth finder.