The argument that I heard was that the sidescan can only do out to the side of the boat as far as it can go down. It makes sense to me. I've also seen a lot of the opposite after searching for reviews. Some people love it for shallow water. I guess the best way of saying it is that it may be just as effective, just not as efficient in shallow water because you're convering a narrower path than you are in deep water.

I'm no expert on the technology and am about 3 years removed from researching for my own install. I'm just relaying the advice I got from members of this forum at the time. The consensus at that time was that it wasn't a necessity for fishing Erie.