Final answer:
When an object is submerged in water, it appears shallower than it actually is due to refraction.
Step-by-step explanation:
When an object is submerged in water, it appears to be at a shallower depth than it actually is due to the phenomenon of refraction. Refraction occurs because light travels at different speeds in different mediums, like air and water. As light passes from one medium to another, its speed changes and it bends, causing the object to be seen at a different angle than its actual position. This bending of light is what makes the object appear to be closer to the surface than it really is.