Harbor of spies

Set in Havana in 1863 during the American Civil War, the Spanish colonial city was alive with intrigue and war-related espionage. The protagonist - a young American ship captain by the name of Everett Townsend - is pulled into the war, not as a Naval Academy midshipman, as he had once hoped, but as the captain of a Havana-based blockade-running schooner. Even as Townsend gets entangled in the war effort, he also finds himself being pulled into the dangerous investigation of a murdered English diplomat which threatens his own life.