1942

Japan began construction of the 5,223-ton I-400 class of submarine aircraft carrier, each of which carried three dive-bomber seaplanes. Designed for attacks against the Panama Canal and the West Coast of the United States. Twelve were planned; only two were built, and did not see any useful service.


1942

On September 13, in what may be the most spectacular – albeit unplanned – submarine event of all time, the Japanese I-19 launched a spread of six torpedoes at the aircraft carrier "Wasp." Three hit, sinking the ship. The others continued running for twelve miles, into another task group, where one caused fatal damage to the destroyer "O'Brien" and other send the battleship "North Carolina" to the shipyard for two months. The sixth cruised on, into the unknown.

1944
The largest ship ever sunk by a submarine: the brand-new aircraft carrier "Shinano," 71,890 tons, November 28, by the U. S. submarine "Archerfish."

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Japanese submarines scored a few important victories – the carriers "Yorktown" and "Wasp," and the last American surface warship sunk, the cruiser "Indianapolis" in late July, 1945; overall, however, they sank only about one-fifth as many ships as did the American submarine force.

On the last day of the Pacific war, Japan had only 33 submarines in commission (excluding midgets), seven of which were in the training command. Except for the midgets, the submarine force had become irrelevant.

http://www.submarine-history.com/NOVAfour.htm

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