A giant squid attack left his wrist broken in five places and his scalp lacerated. As he was covertly filming a poacher in action, his chest was pierced by a bow hook.
But ocean conservationist Scott Cassell says he never once feared for his life. Instead he thrives on dangerous situations.
"It was the most incredible headache," he said of the squid attack. "But human problems are temporary, fleeting and unimportant in the scheme of things. People just do not have a clue what the real problems are."
The 51-year-old explorer, film-maker and army operative who plays with sharks and hunts poachers was speaking to The Straits Times in Tioman, off the east coast of Malaysia.
There, he used his self-modified two-man submersible to study the health of corals.
Based in California, the American has clocked more than 13,000 hours underwater studying the ocean. His documentaries have been aired on Discovery Channel and National Geographic.
He knew from a young age that he wanted to be an ocean explorer, after reading Jules Verne's 20,000 Leagues Under The Sea. Growing up, he was also inspired by the late Jacques Cousteau, one of the most famous ocean explorers of the 20th century.
Mr Cassell's fearless and independent streak does not come from books. It stems from personal experience - his upbringing in an abusive family.
"My 15th birthday present was a broken jaw. I left the door open too long and my father punched me in the face," he said. "I got away as soon as I could and joined the military when I was 17."