Quote Originally Posted by fishervet View Post
Can the 2d sonar images come from any part of the fan shaped span as well? i.e. one side or the other?
I believe the 2d beam is cone shaped and not as wide as the DI. The strong returns in the 2d beam would be more centered in the beam and weaker returns would be more to the edge. You just don't know which edge. Front.back,left or right.
The DI beam is wider but very thin so the returns can be strong throughout the beam but again you cannot tell if it is centered or left or right.
It seems like changing to a higher frequencies would narrow the beams so most returns would be closer to the boat.
Also the depth will change how wide the beam is covering the bottom. 10fow not much coverage, 30fow 3 times more coverage. According to my HB manual a 83khz 60 degree beam coverage is equal to your depth.