The Admiralty regrets... is the phrase used in countless official communiques to announce the loss of one of HM ships. Over 800 British warships have been lost in the 20th century in peace and in war. The circumstances of each loss vary enormously; some involve desperate heroism in battle while others are almost farcical and show something of the black humour which attends such occasions.

No Room for Mistakes is a thoroughly researched account of British and Allied submarine warfare in north European waters at the beginning of World War II. Haarr has compiled research from a wide range of primary sources to create one of the most readable, comprehensive accounts of early war submarine activities. With detailed, accurate maps and many previously unpublished photographs, No Room for Mistakes documents the birth of a new kind of war and the courage of the men who learned to fight it.