A WWII U-boat could clear the surface in 30 seconds.
1,160 U-boats were built by Germany during the 2nd world war. The prefix U in U-boat stands for "Unterseeboot", a German term meaning simply...
Most U-boats of WWII were physically capable of diving to maximum depths of around 150-160 feet, although they seldom ventured that deep unless in an emergency. They could attain this depth in...