Avengers star Chris Hemsworth will be taking a deep dive to swim with sharks for a new National Geographic special.Shark Beach will follow the Australian actor as he embarks on a journey to understand the behavior of the big fish amid increasing attacks on humans Down Under.He will get up close and personal with a variety of shark species, and consult with marine biologists, conservationists, and surfers in his homeland as he explores new technological advances designed to help humans and sharks