A resonant problem
Marine sonar, aircraft landings, the construction of offshore wind farms, and seismic surveys used in oil and gas exploration are all examples of human-caused ocean noise.However, boats, specifically from their propellers, are the most common source.
Cavitation is an effect that occurs when propellers, especially older ones, turn at high speeds. This can cause a drop in pressure on the backside of the propeller, resulting in a lot of bubbles and low-frequency noise.
Boats are also less efficient when there is cavitation because the propeller is using a lot of energy, some of which isn’t helping the boat move forward.