Answer:
7 feet below the surface
Explanation:
Lets consider down direction=+ve(positive) and up direction= -ve (negative).
A scuba diver dives down 15 feet into the ocean, therefore, position of scuba diver would be +15 feet. (as we have considered down direction as positive)
He then swims 8 feet back up towards the surface,now, position of scuba diver would be -8 feet (as we have considered up direction as negative)
So, overall position = 15 - 8 = 7 feet.
Therefore, the position of the scuba diver relative to the surface = 7 feet below the surface.