It has been over 103 years since Australia’s first submarine was lost during World War I. This long sought for discovery follows at least 12 prior attempts to find the wreckage over several decades.
Contact was made by the AE1 with an Australian ship at 2:30 pm on September 14, 1914; the day of its disappearance off the New Guinean Island of New Britain.
The reason for AE1’s sinking remains a mystery and is not presumed combat related. Nearby islanders claimed to have seen what they described as a “devil fish” and “monster” on that day, which quickly appeared before descending back under the dark cover of water.
source Time magazine