Here's why:

* Frequency and Wavelength: The frequency of a wave is the number of waves that pass a point in a given time. Wavelength is the distance between two consecutive crests (or troughs) of a wave. These two are inversely proportional: as frequency increases, wavelength decreases, and vice versa.

* Wave Speed: The speed of a wave is determined by the medium it travels through. In the case of water waves, the speed is primarily determined by the depth of the water.

Therefore, increasing the frequency of a water wave does not increase its speed. It only changes its wavelength.