After a century of war, revolutions, and imperial conquests, 1790s Europe is still embroiled in a battle for control of the sea and colonies. Tall ships navigate familiar and foreign waters, and ambitious young men without rank or status seek their futures in naval commands. First Lieutenant Alexander Clay of the frigate Agrius is self-made, clever, and ready for the new age. But the old world, dominated by patronage, retains a tight hold on advancement.

Midshipman Johnnie Wharton has no idea when he joins HMS St George as a 12-year-old that he is soon to take part in some of the greatest sea battles of Nelsons Royal Navy. Life aboard his next ship HMS Gibraltar is tough for the youngster and he and the other officers face disgrace as his Captain blunders badly at the Battle of the Glorious First of June.

The year 1792. With French revolutionary agents traveling freely but secretly between Ireland and England and war with France inevitable, the English government of Mr. Pitt is desperately anxious to uncover any plots between Irish rebels and the French. Lieutenant James Merriman with his ship, the sloop Aphrodite, is ordered to the Irish Sea to assist the principal treasury agent Mr. Grahame in this work. Merriman is plunged headlong into the world of espionage, and when Grahame is seriously wounded, it falls to Merriman to carry on the investigation.

1793 and Europe is ablaze with war. Thomas Paine Kydd, a young wig-maker from Guildford, is seized by the press gang to be a part of the crew of the 98-gun line-of-battle ship Duke William. The ship sails immediately and Kydd has to learn the harsh realities of shipboard life fast. Despite all that he goes through in danger of tempest and battle he comes to admire the skills and courage of the seamen - taking up the challenge himself to become a true sailor.

December 7, 1941 - America is attacked by the Japanese and dragged into a worldwide struggle for power unlike anything ever seen on Earth. While the United States and the Navy reel from the devastation of Pearl Harbor, the Nazis begin a brutal campaign within sight of the shores of the nation. U-boats prowl the American coast from Maine to the Gulf of Mexico, sinking shipping seemingly unopposed!