If you own one of our high definition side imaging products you can use a down imaging transducer with it to improve your down imaging readings.  High definition side imaging products are only available in our HELIX 9, HELIX 10, HELIX 12, or 800 / 900 / 1100 Series of products.  This is not necessary for any of our MEGA Side Imaging products in the HELIX9, HELIX 10 or HELIX 12 products.  It is also not necessary for the ONIX or SOLIX products.  

You will get readings if DI width is set to wide (this is the default).  If you change to narrow, you will get no readings.

Your 2D readings will not be as good because the 2D element in the DI transducer is smaller; therefore, weaker than the 2D element in the SI transducer

You will not get any SI views that are correct.  

It is best to use this DI transducer in conjunction with a transducer switch  so that you can alternate between the DI imaging transducer and the SI transducer when viewing specific SI and 2D views.   A transducer switch cannot be used with our MEGA Side Imaging transducers.