Light traveling in water is slower than in air?

yes

No. Light travels with the same speed in water. Friction does not apply to light. The intensity reduces though, since the light is scattered and could be focused into different directions as opposed to light in air. If the scattering or disturbance is minimal and the water is totally clear, it will be same. It is similar to foggy or misty air that makes us feel that light is traveling slowly, but light travels the same speed through all non opaque bodies. Intensity varies due to several factors.

Hello James -

I'm afraid Mr What is totally in error. That's OK - happens to me all the time. Not this time though. The speed of light in a vacuum is constant. It is significantly slower in water, resulting in the phenomenon known as refraction - the light rays bend as they cross the boundary between the media - that's how lenses work.