Thread: Question about side imaging

SI on the TM is a valid option as long as one realizes that turning the TM quickly will skew the new SI data being plotted at the top of the SI image... (It doesn't change the SI history data farther down the SI image that has already been plotted in the SI image) ...

Keeping the TM movements slow (and preferably with the boat tracking straight ahead) when needing to discern structure/fish is the goal ...

And then plan the TM movement when there's nothing coming into the new SI data (at the top of the screen) that needs to be studied ...

Rickie

Originally Posted by Pastor

Maybe someone on here can give me an answer before I plop down $800.00. I have a Helix 7 DI (without GPS) in front of boat with transducer mounted on trolling motor. I would like to replace the Helix 7 DI with a Helix 7 SI (with GPS). But I don't know if the SI will work with the transducer mounted on the trolling motor since the trolling motor is used to steer the boat. I know they take images of the bottom in different ways and have watched a couple of YouTube videos but have not seen an answer to my question. Any help will be appreciated. Thanks in advance.

As long as you're going in a straight line, you will get the same results as if the transducer was mounted on the transom. Turn the trolling motor in the slightest degree and your screen image will be skewed temporarily (just like your DI screen image does).

SI is basically an expanded DI ... the narrow fan shaped sonar signal just reaches out at a far greater angle/distance on the SI. That sonar signal is sent out at right angles to the forward facing transducer, so if the transducer is on the trolling motor ... you're signal direction depends on the direction of the trolling motor head.

As I understand it, SI images are best when you are moving at a couple of miles per hour ... but, I do know that many members do have SI units on their trolling motors, so it must work OK at slower speeds. I don't know, as I don't have an SI unit ... just a DI unit, with the transducer mounted on the trolling motor.

SI on the trolling motor is a great tool. For example.....sometimes fish don't hold right on a brush pile. If you approach the brush with SI, you may see the fish of to one side or the other.....You can also move the trolling motor to scan around. Sometimes you will spot other brush off to the side of where you are fishing.
I have seen some really good images at very slow speeds on a trolling motor.....reducing the chart speed will keep the scale on the screen more accurate.....but it's not necessarily about pretty pictures .... it's about having more information.

Thanks for the replies guys. Now all I have to do is decide if I want to drop that kind money on a Helix 7 SI for my wife's valentine's present. Hehehe!

Haha!! It depends on how much you like the couch I guess.

Not to hijack, but how does DI work on the trolling motor when your moving and turning the trolling motor constantly. Like when your trying to hold over a deep brush pile in the wind.

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MATHEWJP,I DO IT WITH 2D AND DI ALL THE TIME,ONE WILL HELP THE OTHER UNIT,LIKE ALREADY SAID NOT BEST PIC BUT BEING IN BOAT WHILE DOING IT THE INTERPRETATION IS NOT THAT HARD,CAN TELL FISH FROM BRUSH AND WHAT MORE WOULD YOU NEED

Being DI is a very narrow beam there is no way to tell how the fish react to your presentation, cannot keep the jig in the beam. That is why when I am fishing vertical I use 2D I can see my jig and watch how the fish react and tell me how to change presentation or bait. Me personally DI is worthless because I have used SI to know the fish are in that spot before hand unless it is ultra shallow.

BRICK,I AM SORRY TO DISAGREE WITH YOU,I BEEN USING 2D AND DI AS LONG AS THEY CAME OUT,I FISH OVER BP MOST OF MY FISHING AND DOCKS THE REST,DI WILL LOOK INTO BP WHILE SETTING STILL WHILE 2D SEE THE FISH OVER BP YET I SEE FISH IN BP WITH 2D AND DI,YOU JUST HAVE TO KNOW HOW TO INTERPRET,FISH LAST WEEK IN BP NEAR A BLUFF AND THE FISH MOVED SO I MOVE TO BLUFF ABOUT 15 FEET AWAY,COULD NOT SEE FISH NEAR BLUFF WITH 2D BECAUSE 2D PICK UP BLUFF FROM 15 T0 35 FEET DEEP,SO I TURN DI SO IT WOULD BE GOING WITH THE BLUFF AND IT THEN WENT TO 35 FEET DEEP AND I COULD SEE THE FISH AT ABOUT 28 FEET DEEP AND BEGIN TO CATCH THEM AGAIN,THESE UNITS WILL TELL US MORE THAN WE THINK THEY WILL,JUST HAVE TO LEARN WHAT IT IS TELLING YOU,I GO OVER BP AND DI TELL ME IF FISH ARE THERE AND ABOUT THE SIZE SO I KNOW WEATHER TO STOP OR NOT UNLESS IT IS A THICK PILE ,THEN I HAVE TO FISH IT ALSO,I DO BRIDGE PILINGS THE SAME WAY WITH DI IF THEY CLEAN TIGHT TO THE PILING,CAN SEE THEM WHEN 2D WILL NOT SHOW ANY