jacques cousteau himself is said to have seen only two. they're giant sharks. much bigger than great whites. but this shark is far from jaws. they're whale sharks and, in fact, they are gentle giants though it's still plenty exciting to see one up close. just ask my co-anchor bill weir as he discovered for our series, "into the wild." >> reporter: for centuries, fishermen on this gorgeous island would come to a church made of coral and pray for protection from the biggest beast in the sea. the low cams in these village ss are talking about the wheel shark. one of the most ancient and mysterious creatures on the planet. glassy seas. perfect day to mingle with sharks. >> if we see whale sharks we interact with as many as we can. >> reporter: this is the boat of choice in the philippines. and this one takes us past a smoldering volcano. into a bay where the allure of the giant fish has created a new vocation. the whale shark interaction officer. >> because this boat has no propeller guard and then it is very dangerous. >> reporter: how fast will the whale shark mo