Final answer:
When an object is submerged in water, it appears shallower than it actually is because of refraction.
Step-by-step explanation:
When an object is submerged in water, it appears to be at a depth shallower than it actually is. This is because of the phenomenon of refraction, where light bends when it passes from one medium to another with a different optical density. In the case of water, light bends as it enters the water and again as it exits the water, causing the object to appear higher than its actual position.