Answer:
322 feet
Explanation:
if the question was two positive heights, you would subtract, and you still do. we find how many inches my father is taller than me by subtracting my height from his, and the same applies to this, though the submarine, being below sea level is at a negative height. when you subtract a negative, it's the same as adding a positive.
264 - (-58)
264 + 58 = 322