Question

If you were trying to kill a fish witha a spear, woukd you ain where you see the fish?

Answer 1

No by the time you reacted refraction would change its location
So you would probably aim in front of the fish if you were to kill it with a spear,
So as you react the fish won't pass you

Answer 2

No, you can't aim where you see the fish, because refraction will change the position of the fish and make it appear in a different position from where it actually is.

Hope this helps!