Adam Walker is an experienced open-water long distance swimmer.  He was on a sixteen mile swim through the Cook Strait in New Zealand when he spotted a shark near him.  Also close by was a pod of dolphins.  The dolphins guarded Adam for an hour as he continued his journey and made it safely to shore.  Who in their right mind swims for 16 miles in shark infested waters!!??  Not me.  Careful Adam, there won't always be a pod of dolphins around to keep you safe.