SI is invaluable in finding new structure out to the sides of the boat ....even in shallow water...

The 800kHz frequency is somewhat limited in side to side distance (in real shallow water) due to the fact the total beam coverage is only 130°...

Whereas the 455kahz frequency has a total beam coverage of 180°...(but the image detail just won't be as crisp as the 800kHz)..

Rickie