Attend enough new-product presentations and it can feel like successive generations of technology strive to refine rather than revolutionize. The perception makes sense given the advanced state of today’s marine electronics, but it’s a great feeling to walk away from a new-product announcement gobsmacked by a breakthrough. This happened to me at last fall’s METS trade show in Amsterdam during a Humminbird presentation for its Mega Imaging sonar. The lights dimmed, the slideshow started, and my jaw promptly found the floor. I stared, mesmerized, at photographlike sonar images of the bottom structure and — in some cases — shadows on a lake bed cast by rocks, trees and fish.