Final answer:
An object in water appears shallower than its actual depth due to the refraction of light, as light bends towards the normal when transitioning from water to air.
Step-by-step explanation:
The phenomenon responsible for an object appearing shallower in water than it actually is, is called refraction. When light travels from water to air, it changes speed due to the different densities of the two mediums, and consequently, it bends. This bending occurs towards the normal because water has a greater index of refraction than air.
As a result, the path of light from the object is altered, making the object appear closer to the surface or at a depth that is more shallow than its true position.
The reason why an object in water always appears to be at a depth that is more shallow than it actually is due to refraction of light. When light passes from air to water, it bends towards the normal at the interface between the two mediums. This bending of light causes the apparent position of the object to be above its actual position, leading to the object appearing at a shallower depth.