When sound waves travel from air into water, the speed of the sound waves generally increases. This phenomenon is due to the difference in the density and compressibility of air and water.
In general, sound travels faster in denser and less compressible mediums. Water is denser than air and has a higher bulk modulus, which measures its resistance to compression. Consequently, sound waves encounter a medium with higher density and less compressibility when they transition from air to water.
The speed of sound in air at room temperature is approximately 343 meters per second (m/s). In contrast, the speed of sound in water at the same temperature is about 1,484 m/s, which is more than four times faster than in air. Therefore, when sound waves cross the air-water boundary, they experience an increase in speed.
It's worth noting that the exact speed of sound in water can vary with factors such as temperature, salinity, and pressure. However, in most cases, sound waves will propagate faster in water compared to air.