Radiofrequency (RF) waves can travel through water, but their propagation and attenuation characteristics are different compared to their behavior in air or vacuum.
In general, RF waves can propagate through water, but the degree of penetration and the amount of signal attenuation depend on the frequency of the waves and the properties of the water itself. The behavior of RF waves in water can be explained by understanding their interaction with the water molecules.
At lower frequencies, such as extremely low frequency (ELF) and very low frequency (VLF), RF waves can penetrate water to considerable depths. These waves have long wavelengths and can travel through water with relatively low attenuation. They are used, for example, in underwater communication systems for submarines.
However, at higher frequencies, such as microwave frequencies commonly used in wireless communication (e.g., Wi-Fi or Bluetooth), RF waves have shorter wavelengths. These waves interact more strongly with water molecules, causing increased absorption and attenuation. As a result, their penetration depth into water is significantly reduced.
In practical terms, this means that higher frequency RF waves, such as those used for Wi-Fi or cellular communication, can only penetrate water to a limited extent. Even a few centimeters of water can cause significant signal attenuation. Consequently, wireless signals generally do not propagate well underwater, and their range and performance are severely limited.
Specialized techniques and technologies are required to establish reliable wireless communication in underwater environments, such as using acoustic or optical signals rather than RF waves.
It's worth noting that the behavior of RF waves in water can also depend on factors such as the salinity and temperature of the water, as well as the specific frequency and power of the RF signals involved.