Dark Pacific: Final Fathom

On the man-made island fortress known as Sea Base, enemies are threatening from without and within. China seems poised to invade the island of Taiwan, with its ships and submarines swarming the area. And when an escort of American and British planes is ambushed by Chinese fighters, Sea Base prepares itself for a showdown. But the battle may already be lost. An assassin has infiltrated Sea Base to take out key personnel, and one of their own crewmembers may be a foreign agent.
  Now, Sea Base will have to fight the enemy on two fronts if it is to survive.   "David Meadows is the real thing."-Stephen Coonts   "Great battle scenes, believable heroes, plus villains you'll love to hate."-Joe Buff, author of Deep Sound Channel