Which of the statements concerning sound transmission underwater is incorrect?

The statement concerning sound transmission underwater that is incorrect is that divers find it easy to talk to each other directly through the water. In reality, while sound does travel well through water, direct verbal communication between divers is challenging. This difficulty arises because sound waves are affected by factors like water pressure, density, and temperature, which can distort and attenuate speech. Furthermore, human speech relies on both sound and its associated visual cues, which are diminished underwater.

In contrast, the other statements highlight aspects of underwater acoustics that are well-established: sound does indeed travel farther in water than in air, divers may struggle with determining the direction of sounds due to how sound waves behave in water, and sound does travel about four times faster underwater compared to its speed in air. All these statements reflect the unique properties of sound transmission in aquatic environments.