Refraction causes the bottom of the pool to appear closer than it actually is.
Work Step by Step
See Figure 23-22b. The child doesn’t know about refraction, and is likely to underestimate the depth of the pool. Light rays that come from the bottom of the pool (or her toy) will bend away from the normal as they enter air and move faster. The source of the rays appears to be higher up, closer to the surface than it actually is.