Complex sentence: By 1977 Mattison started competing in surf competitions at the age of eight in Jacksonville Beach, Florida United States, Sean grew up surfing on the east coast in the ESA also known as Eastern Surfing Association.
Split into simpler sentences: By 1977 Mattison started competing in surf competitions at the age of eight in Jacksonville Beach, Florida. Mattison grew up surfing on the east coast in the ESA also known as Eastern Surfing Association.