The area of the original rectangle is 8 yards x 7 yards = 56 square yards.
The area of the removed rectangle is 3 yards x 3 yards = 9 square yards.
Therefore, the area of the swimming pool is 56 square yards - 9 square yards = 47 square yards.
None of the provided options match the correct answer. Therefore, a correct option should be: 47 square yards.