Although water is often described as nearly incompressible, it can still transmit sound waves. While it is true that water is less compressible than gases like air, it does exhibit some compressibility under high-pressure conditions.
In the case of sound waves in water, the particles of the medium (water molecules) do undergo slight compressions and rarefactions as the sound wave passes through. These compressions and rarefactions are responsible for the transmission of sound energy.
However, it is important to note that the extent of compression and rarefaction in water is significantly smaller compared to gases. In other words, the amplitude of the compressions and rarefactions in water is much smaller than in air. This is due to the higher density and intermolecular forces present in liquids, making them more resistant to compression.
In water, the molecules are tightly packed, and the intermolecular forces between them prevent large-scale compression. Consequently, the speed of sound in water is much faster than in air because the particles can transmit the compressions and rarefactions more efficiently.
So, while water is not as compressible as gases, it still exhibits enough compressibility to allow for the transmission of sound waves.