In 1914 Ireland was a naval backwater with only one base of any size in Co Cork.
However, by the end of World War I, there were 18 naval bases operated by thousands of personnel, hundreds of ships of all sizes and dozens of aircraft.
Ireland had become a crucial theatre of the war, fundamental in winning the campaign to defeat the German U-boats.
How and why did this come about?In this well researched and readable new book, Guy Warner tells the story of how vital success at sea in the waters around Ireland became.
If Germany could break or even seriously disrupt the flow of merchant vessels then Britain's ability to have waged war, or indeed feed its population, would have been rendered either difficult or impossible.
As well as examining the growth in Royal Navy anti-submarine activities and the roles of key personnel, it also looks at the important part played by rapidly developing technology and the measures devised to counter this new enemy - the U-boat.
A fascinating new book that also highlights the role the US Navy played from 1917 onwards and comes fully illustrated with many rare and previously unpublished images. "The phrase that Admiral Jellicoe `could have lost the war in an afternoon' in the North Sea is well known.
From Guy's research we now know that had Admiral Sir Lewis Bayly and the patrol forces under his command around the Irish coast not been as efficient and operationally successful as they were, defeat might have taken a few weeks longer but would have been just as certain." Commander David Hobbs