April 12, 1861. With one jerk of a lanyard, one shell arching into the sky, years of tension explode into civil war. And for those men who do not know in which direction their loyalty calls them, it is a time for decisions. Such a one is Lieutenant Samuel Bowater, an officer of the U.S. Navy and a native of Charleston, South Carolina.

Hard-pressed to abandon the oath he swore to the United States, but unable to fight against his home state, Bowater accepts a commission in the nascent Confederate Navy, where captains who once strode the quarterdecks of the world's most powerful ships are now assuming command of paddle wheelers and tow-boats. Taking charge of the armed tugboat Cape Fear, and then the iron-clad Yazoo River, Bowater and his men, against overwhelming odds, engage in the waterborne fight for Southern independence.