Thread: Sonar and DI Dont Show Same Thing?

So let's make some distinctions here ...

The OP lists his unit as HELIX 7 SI ...

The only HB SI units that have a dedicated "down pointing" DI piezo are SOLIX, ONIX, and MEGA 9, 10, and 12 ...

All other HB SI units derive the DI view data from the "side pointing" SI piezoes ...

This basically means that any targets directly under the xducer are residing in the outer fringes (less sound strength) of the SI beam sound pulse ...

Simply put - less sound strength area = less echo reflected = less echo data to display in the SI unit DI view ...

Here is the beam form for the right SI pulse showing the Main Axis (strongest part) of the right SI sound pulse ...



Mirror the above depiction for the left SI sound pulse and realize than any targets under the boat are just not reflecting as much of the SI sound pulse from that area under the xducer ... Therefore, not as much echo data to display in the HB SI unit DI view ...

Rickie