HNLMS O 20

O 20, laid down as K XX, was a O 19-class submarine of the Royal Netherlands Navy that saw service during World War II. O 20 along with her sister ship O 19 were the first boats in the world to be equipped with a submarine snorkel that allowed the submarine to run its diesel engines while submerged.

HNLMS O 20

O 20, laid down as K XX, was a O 19-class submarine of the Royal Netherlands Navy that saw service during World War II. O 20 along with her sister ship O 19 were the first boats in the world to be equipped with a submarine snorkel that allowed the submarine to run its diesel engines while submerged.