A fish finder’s detection area is not simply “the bigger, the better.” Instead, it closely depends on the beam angle, depth, and onboard algorithms. Take the Lucky fish finder as an example: its 90° beam angle combined with a maximum detection depth of 45 meters allows it to cover approximately 2,850 square meters of underwater area (calculation logic: sector area = πr² × (θ/360), i.e., 3.14 × 45² × 0.25 ≈ 2,850㎡)—equivalent to the size of six standard basketball courts.

Key Parameter Breakdown:
1.Beam Angle Determines Lateral Width:
Lucky’s 90° beam covers 45° on each side of the vessel. Field tests show that at a cruising speed of 8 knots, each sonar pulse (emitted every 0.5 seconds) spans up to 60 meters in width, thanks to a lateral spread speed of 120 meters/second.
2.Depth Affects Vertical Accuracy:
At a depth of 45 meters, Lucky’s sonar can penetrate muddy bottoms. In real-world tests, it achieved a 92% detection rate for carp schools. However, bottom contour errors require correction using a formula (e.g., “detection range = actual depth × 1.3”).
3.Algorithms Filter Out False Signals:
Lucky’s current-resistant algorithm can suppress interference from weeds and bubbles. In rapid current conditions, its fish school detection accuracy outperforms competitors by over 30%.