Despite ineffectual attempt by both the Russian and Japanese navies during the Russo-Japanese War (1904-1905) to employ "submarine torpedo boats" in Far Eastern waters, modern submarines received their first real baptism of fire in WW I (1914-1918).
Even with the global proliferation of submarines during the first few years of the 20th century, it was the Germans and British who first demonstrated their dangerous potential for undersea warfare in the Atlantic and Mediterranean during 1914 and 1915.........
Well I'll let the above slide on into the article itself....that is if your interested in this sort of history.
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