Yes.
The propagation speed of electromagnetic waves v=1/√με≈c/√εr
μ is the magnetic permeability of the medium where the electromagnetic waves are found, ε is the dielectric constant, and the following is a simplification In the formula, c is the speed of light and εr is the dielectric constant of the medium where the electromagnetic wave is located relative to air, which is actually a multiple.
The speed of propagation of electromagnetic waves in a vacuum or in air is the fastest, that is to say the speed of light.
The relative dielectric constant of water is approximately 81 (that is, the dielectric constant of water is 81 times that of air), so the speed of Electromagnetic waves in water are 1/9 that of air, and the frequency remains unchanged. Wavelength λ = v/f, the corresponding wavelength is also 1/9 that of air.
Thus, from water to air, the wavelength becomeslonger.
Three-quarters of c, that is to say v, is equal to 2 point 25 times 10 to the power of 8 meters per second. The speed of electromagnetic waves in water is much slower than that of air. Water is a medium with a high dielectric constant. The speed of electromagnetic waves in water is three-quarters of c, that is, v is equal to 2 points 25 times. 10 times 8 square meters per second.