If yes, then what are the factors which help EM waves to pass easily and the factors which resist these waves from passing smoothly inside the ocean..
EM waves pass through free space. Thus, it needs no medium for its propagation. EM waves are categorized on the basis of frequency by which they interact with matter. At high frequencies EM waves are attenuated severely.
EM waves propagating in Ocean will be attenuated heavily. Water having a high dielectric constant (80) will reflect all of the energy (Water has a high resistivity (182 kΩ·m²/m) leading to formation of standing waves ( impedance mismatch ). Salt which is conductive will not allow EM waves to penetrate through (high conductivity = low skin depth).
Propagation is possible to a greater distance by low frequency EM waves and pure water.
Yes, it is possible to have a communication through EM waves inside water.
However, it is limited to smaller distances. The distance depends upon water attenuation, conductivity, permittivity and transmitted signal power level.
Eg: Submarines.
Yes, I agree with Mr. Suhas, EM wave propagation doesn't require medium, but when it travels through the medium, it gets highly attenuated according to dielectric constant of medium. Water has high dielectric constant, responsible for more attenuation which means wave can't travel a far distance through the water.
As far as I know the EM-waves actually are used for a communication with submarines (military). For this purpose, to my knowledge, the carrier frequency is in the range of tens-hundreds kHz. As it was mentioned above, the sea water is conductive and strongly attenuates EM wave. On the other hand, EM wave must penetrate inside the sea water at the skin depth. Therefore, making the wavelength larger, one can increase this depth of wave penetration. I assume that it is the reason why such a low frequency is used for a submarine communication.
Mr Nadir . it is possible we can communicate in water by using the EM wave first we have to set system the it is possible .
EM waves propagating in Ocean will be attenuated heavily. that why Water having a high dielectric constant . so it will reflect all of the energy (Water has a high resistivity of 182 kΩ·m²/m) that why leading to formation of standing waves like impedance mismatch and other factors like . Salt which is conductive will not allow EM waves to penetrate through high conductivity = low skin depth.
Yes it is possible. However you should keep the following in mind.
1. Higher frequency signals attenuate quicker in water whereas lower frequency signals can propagate longer.
2. However, for lower frequencies we need larger antennae.
So basically you have a trade off between antennae size and range.
RF and/or optical waves can be used for relatively short range communication under water, but for longer distance, acoustic seems a better choice.
You can use Molecular Communication for underwater communication. It's not been practical yet
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