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.

Posted next to HMS Monarch, the 74-gun third rate is sent to the West Indies and survives a monstrous hurricane, with the ship-of-the-line nearly wrecked. Back in home waters, Wharton leaves Monarch and is sent to the fast brig-sloop Magpie, commanded by the pugnacious Captain Sotherton to assist in the British blockade of the French coast.

Sea fights with French ships off Brittany follow and then the capture of a valuable Dutch merchantman. Wharton's share of the prize money from the sale of the Dutch ships cargo of wine and brandy help smooth the career ahead in the Royal Navy for this son of a Devon doctor.

Finally, Johnnie Wharton plays a key role in landing one of Prime Minister William Pitts spies on mainland France and the rescue of another with vital information about Napoleons plans to invade and capture Egypt to block Britains route to India.