Explain what parallel medium boundaries do to the path of the wave after it travels through both boundaries. (air and water)

The boundaries cause the waves to change direction an effect called refraction.

Explanation:

When a wave crosses a boundary between different materials, the speed of the wave and its wavelength changes. When passing from air to water the two properties (speed and wavelength) decreases, and the wave is observed to change direction as it crosses the boundary between the two material. The bending of the wave is called refraction.