An echo sounder error due to turbulence on water is called what?

• A. Aeration
• B. Reflection
• C. Refraction
• D. Interference

Answer: (A)

Air bubbles formed by turbulent water introduce random backscatter that disrupts the clean sonar returns. When an echo sounder sends a pulse into turbulent water, the entrained air creates many tiny reflectors, causing noisy, distorted echoes and unreliable depth readings. This specific issue is called aeration, the presence of air bubbles that scatter the acoustic energy.

Reflection refers to sound bouncing off a boundary like the seabed or surface, which is a normal, intended phenomenon. Refraction is the bending of sound paths as speed changes with depth. Interference is the combination of waves from multiple paths that can amplify or cancel signals. These describe different acoustic behaviors and do not capture the bubble-related noise produced by turbulence, which is aeration.