Dang ... I had to come all the way to Mississippi whew ... Just kidding ... Doug asked me to pop in and help ...

HB SI core units do not have a "down pointing" piezo ... HB DI units do ...

Therefore the DI image in a SI core unit is a computer generated blend of the left and right SI image ...

In my seminars I like to explain HB imaging Sonar beams (DI and SI) as similar to a flashlight ... Casting a thin slice beam ..

If we take a flashlight and shine it at our shoes (as in a HB DI unit) ... Our shoes would be very bright ...

If we take a flashlight in each hand and shine them at our buddies shoes standing next to us (as in a HB SI unit) ... No amount of computer generating can make our own shoes very bright ...because neither flashlight is illuminating our own shoes very well ...

DI from a dedicated "down pointing" piezo will always be better than "DI from SI" ...simply because a DI piezo is pointing right at the stuff directly under the boat ... The SI piezoes are pointing at the stuff out to the sides ...

Rickie