- Submarine World Network by Ron Martini - This is the largest submarine site in the world with over 1000 lints to all things submarine with emphasis on history, current/past boat pages and veteran aids and site.
- The U-Boat War 1939-1945 - Los submarinos alemanes en la II Guerra Mundial.
- Battle against the U-Boat in the American Theatre
- Canonesa, Convoy HX72 & U-100 - Chronicles a U-boat attack on an allied merchant convoy in 1940 during the Battle of the Atlantic. Draws on witness accounts and official records.
- The U-boat Bases - A complete web site about the U-boat bases of the Second World War in France. Many photos, descriptions, maps...
- U-boat Net - The U-boat War 1939-1945 - Everything about the German submarines of World War II you could want to know. Includes data for all of the subs and their histories. Recommended to anyone interested in the topic.
- Submarinos alemanes
- Battle of the Atlantic