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Why does sound travel faster in seawater than in air?

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seawater Clear ocean water near a beach on Grand Bahama Island in The Bahamas.

Sound travels significantly faster in seawater than in air because of the physical properties of the medium. The speed of sound in any material is determined by the square root of its elasticity (or bulk modulus) divided by its density.123

Because water is only slightly compressible, it possesses a high degree of elasticity, which allows it to conduct sound waves rapidly. Furthermore, because the particles in liquids are packed much more closely together than those in gases, sound waves are transmitted more efficiently through seawater.14

While the speed of sound in air is approximately 331.29 metres per second at 0 °C, it ranges between 1,450 and 1,570 metres per second in the ocean. This velocity in seawater is not constant; it fluctuates based on temperature, salinity, and pressure, all of which influence the water's density and elasticity.145