Complex sentence: Butch hits Tom in return, causing Tom to turn inside out in his bathing suit and float upside down, but after Butch hits Tom again, Tom vanquishes Butch with an accurate swing of the anchor, winning his girlfriend's heart back.
Split into simpler sentences: Butch hits Tom in return, causing Tom to turn inside out in his bathing suit and float upside down. After Butch hits Tom again, Tom vanquishes Butch with an accurate swing of the anchor, winning his girlfriend's heart back.