Starsea Invaders Series by G. Harry Stine

The Pacific Island port of Makasar used to be a fairly peaceful outpost of the United States Navy. But now, entire American families are vanishing without a trace and no one has any ideas about where they might be. William M. Corry, captain of the super-sub U.S.S. Shenandoah has orders to get to the bottom of the mysterious disappearances... moreThe Pacific Island port of Makasar used to be a fairly peaceful outpost of the United States Navy. But now, entire American families are vanishing without a trace and no one has any ideas about where they might be. William M. Corry, captain of the super-sub U.S.S. Shenandoah has orders to get to the bottom of the mysterious disappearances. At first, he suspects the unpredictable Chinese troopers patrolling the area, but after a little investigating, Corry realizes that the disappearances of the Americans cannot be the fault of the Chinese—they are as worried as he is. Corry refuses to believe the wild rumors of native cannibals…until he accidentally unearths the real enemy: a force with power beyond anything humankind has ever known! less

The hunt was on--William M. Corry, captain of the American super-sub, the U.S.S. Shenandoah, was certain his new mission was not as simple as it first seemed. His initial orders were for a shakedown cruise, but those were quickly countermanded by another directive to proceed to the Solomon Islands. Yet Corry's gut feeling was that this was all a coverup for something far bigger... moreThe hunt was on--William M. Corry, captain of the American super-sub, the U.S.S. Shenandoah, was certain his new mission was not as simple as it first seemed. His initial orders were for a shakedown cruise, but those were quickly countermanded by another directive to proceed to the Solomon Islands. Yet Corry's gut feeling was that this was all a coverup for something far bigger. And he was about to be proved right! Told to rendezvous with and take on board a scientific team, Corry learned that the Shenandoah was at last going to be allowed to track down the alien invaders who were based beneath the sea--and this time they were going to bring one of the creatures back alive! less

Carrying a powerful cargo that could result in the destruction of twenty-first-century humankind, William M. Corry, the captain of an American super-sub, is distraught by orders that send him into the heart of enemy territory. Original.