Based on a true story: When a green sea turtle spotted some fishing line, he swam over to investigate the shiny, sparkly thing. But the stringy stuff got wrapped around one of his flippers, and the more he struggled, the tighter it got. He couldn't get loose! Soon he was too weak to dive for food, or swim to the ocean surface for air. Exhausted, the young sea turtle struggled onto the beach to rest.

However, there were much larger obstacles and challenges awaiting him outside of his ocean home. His injured fin was so damaged it had to be removed. With the help of veterinarians at a nearby aquatic center, who name him Mahi, he is slowly nursed back to health. The staff named him Mahi, which means "mighty". They help Mahi relearn to dive and eat with only three flippers. After two years, he finally heals completely and is released back into the ocean.