The Trench — Paul Mannering

We know more about other planets than we do about the world at the bottom of our own oceans. Marine Biolgist Michael Armitage is recruited to investigate an emergency at a secret military research facility, deep in the Kermadec Trench, 18,000 feet below the surface of the Pacific Ocean. Now trapped with a squad of Marines and the few survivors, they must fight to survive and discover the terrifying secret that lurks in the darkness of The Trench.