“It works best in water under 300 feet, but deeper than that, structure definition begins to diminish,” he says of Simrad’s StructureScan 3D. But he uses it anyway, and for a particular purpose: StructureScan 3D can read sideways out to 600 feet and mark fish at long range. “If you’re running in the opposite direction to the fish, it will show up as a red dot,” he says. “If you’re traveling parallel in the same direction, there’s more sonar on
the target and it will show up as a streak.