First of a two-part documentary in which David Hayman uncovers the story of the battle for control of the North Sea during the First World War.

As the Great War began, the Royal Navy rushed to Orkney's great natural harbour, Scapa Flow.

David Hayman uncovers the compelling characters of the little-known naval war - cautious Admiral Jellicoe and Admiral Beatty, a playboy.

The story of great technologies and epic battles for control of the North Sea.