Sea Raiders - Carey Fessler

Kidnapped by a rogue submarine crew with mutation magic, twelve-year-old Aussie cousins Emma and Scott, along with sixteen-year-old Harrison, escaped their captors by swimming to a remote tropical island, where they fought off man-eating monster lizards and a village full of headhunters armed with blowpipes and endowed with deadly aim …

Now taken hostage during a modern-day pirate raid, Scott and Emma fight for their lives and swim back to the last place on earth they want to return to—Dragon Island. Meanwhile, Harrison faces his fears and tries to thwart the pirates. Can the three young survivors stay alive and raise the alarm—and return home to their families?