Thirteen-year-old Tammy Aiko and her friends have started a Marine Science Club at their school. It's going to be a lot of fun! The only problem? No one wants to join. But when the friends sneak into a mysterious cove at the beach, they come face-to-face with not one, but three wild sharks! The sharks need the humans' help-and as it turns out, Tammy needs their help, too.