Final answer:
Cam is 11.6 meters below the surface of the water, calculated by subtracting Cam's position above Ben (4.2 meters) from Ben's depth (15.8 meters).
Step-by-step explanation:
The student's question involves finding Cam's position relative to the water's surface, given Ben's position below the surface and Cam's position above Ben. Ben is at a depth of 15.8 meters, and Cam is situated 4.2 meters above Ben. To find Cam's position relative to the surface, we subtract Cam's position from Ben's.
Ben's depth = 15.8 meters
Cam's position above Ben = 4.2 meters
Cam's depth relative to the surface = Ben's depth - Cam's position above Ben
15.8 meters - 4.2 meters = 11.6 meters
Therefore, Cam is 11.6 meters below the surface of the water.