By A Mystery Man Writer
The U-boat War in World War Two (Kriegsmarine, 1939-1945) and World War One (Kaiserliche Marine, 1914-1918) and the Allied efforts to counter the threat. Over 40.000 pages on the officers, the boats, technology and the Allied efforts to counter the U-boat threat.
U-boat Deck guns - Technical pages - German U-boats of WWII - Kriegsmarine
How US Sailors Saved U-Boat, Enigma, Codebooks in Daring High-Sea Raid
What the postman brought today (Armorama) - Armor/AFV - KitMaker Network
U-boat, German Submarine Warfare in WWI & WWII
Battle of the Atlantic: Archaeology of an Underwater WWII Battlefield: Mission Logs: September 4: NOAA Office of Ocean Exploration and Research
Munizionamento Cannone Sommergibili Regia Marina - Tecnica - Betasom - XI Gruppo Sommergibili Atlantici
Exclusive: Wreck of fabled WWI German U-boat found off Virginia
המערכה באוקיינוס האטלנטי (1939–1945) - מרכיבי הקרב – ויקיפדיה
German U-Boat Deck Guns - 88mm & 105mm Specification