The Naval Historical Branch has made the 1939 Admiralty War Diaries available to download, with the stated intention of making further diaries available as soon as possible. https://www.royalnavy.mod.uk/our-or...tions/navy-command-hq/naval-historical-branch These are accompanied by a bibliographical essay by historian Edward Hampshire of the Naval Historical Branch. Edited to update the link. n.b. the official histories 'Merchant Shipping and the Demands of War', Behrens and 'War at Sea 1939-1945', Roskill have since been added too.
If you are wanting later editions, the Admiralty War Diaries 1939-45 are available on Fold 3. They also have the subject index cards. Tim
Excuse my ignorance Tim, but I'm a little puzzled by what you've written. Fold 3?. Are these other diaries located at the National Archives, Richmond?
Admiralty War Diaries are at the National Archives, Kew, Richmond. Fold3 - Fold3 - Historical military records Admiralty War Diaries are located by scrolling WWII - WWII War Diaries - A - Admiralty War Diaries Tim