Sonar Dead Zones Explained: Why You Can't See Fish on Slopes & Drop-offs

Are you missing fish that are right below your boat? Even with the best fish finder, physics can create a "Blind Spot" or "Cone of Shadow" where targets become invisible. In this video, I explain exactly how the Sonar Dead Zone works using a clear graphical representation. We will analyze the "Red Band" (your bottom return) and understand why fish disappear when you are fishing over slopes, humps, or drop-offs. You will learn: What is the "Cone of Shadow" and how it is generated. The difference between the closest point (Yellow Arrow) and the farthest point (Blue Arrow). Why the bottom line gets thicker on slopes. The difference between High and Low Frequency (CHIRP) regarding the blind spot. BONUS: How the "Shift" function affects your view of the cone. This is a technical deep-dive masterclass for anglers who want to understand their electronics fully. ⏱️ Timestamps: 0:00 Intro: The Sonar Blind Spot 0:45 The Setup: Transducer & Seabed Geometry 1:30 The "Red Band" Explained (Closest vs Farthest Point) 2:50 What happens on Shallows & Slopes? 3:45 Why Fish Disappear inside the Bottom Line 5:20 Analyzing the Thickness of the Seabed Return 6:50 High Frequency vs Low Frequency (Beam Width effects) 8:10 BONUS: Understanding the SHIFT function 9:45 The Final Challenge: What happens over a Hole? #FishFinder #Sonar #MarineElectronics #FishingTech #MrFishFinder #Garmin #Lowrance #Simrad #Furuno #DeadZone #FishFinder #Sonar #MarineElectronics #FishingTech #MrFishFinder #Garmin #Lowrance #Simrad #Furuno #DeadZone