Beautiful FVX work of British independent visual effects company Fluid Pictures about Japan's World War II Submarine I-400-class for National Geographic Channel of The United States in 2009 with opening theme from German Film Das Boot. This movie is edited from Largest Dams's The Largest Submarine in World War II( https://www.youtube.com/watch?v=mBx2Bu-jnOs ) and HiVision7's【HD】日本軍の極秘潜水艦 Japan's Secret Weapon part1-8 ( https://www.youtube.com/watch?v=ZX_srbvRqvQ&list=PL8980749B4A801C1A ) without their permissions.Music：Klaus Doldinger / Titel from Das Boot (1981) 伊四百型潜水艦http://ja.wikipedia.org/wiki/伊四百型潜水艦