Pilot  Ensign Masaharu Yokoyama (KIA)
Crew  Petty Officer 2nd Class Sadamu Kamita (KIA)
Scuttled  December 8, 1941

Sub History
Built in Kure during 1938. Delivered to the Imperial Japanese Navy (IJN) as HA-16 Type A Midget Submarine. Known to the U.S. Navy as "Midget E", the 5th midget submarine encountered during the attack on Pearl Harbor.

Wartime History
On December 7, 1941 one of five midget subs attached to five I-class "mother" submarines (I-16, I-18, I-20, I-22 and I-24) to be launched 5-6 hours before the aerial attack off Pearl Harbor as a "Special Attack Unit" that would attack any ships attempting to sortie or submerged navigate counterclockwise around Ford Island, firing their torpedoes then rendezvous that night with the mother submarines seven miles west of Lanai Island.

Sinking History
On December 7, 1941 at 12:42am I-16 arrived at the launch point seven miles south-southwest of the entrance to Pearl Harbor, and launches this Midget Submarine piloted by Lt(jg) Yokoyama Masaharu with PO2C Ueda Sadamu. This was the first of the five midget submarines launched at the start of the Hawaii Operation.

The precise fate of this submarine is unknown. It is believed it entered Pearl Harbor, fired both torpedoes at Battleship Row then entered West Loch. Trapped, the crew scuttled the submarine and killed themselves.

At 10:41pm, I-16 received a message "se, se, se” (short for seiko, seiko, seiko - success, success, success) indicating the aerial attack was a success. Reception was poor and the message might have come from any of the midget submarines. On December 8, 1941 at 12:51am I-16 receives a message thought to be from this midget submarine "unable to navigate". No other transmissions were received.

The ultimate fate of this submarine is unknown. Likely, it was deliberately scuttled by the crew or sunk into West Loch in the early morning hours of December 8, 1941. After the attack, an unexploded torpedo dud of the type used by the Type A midget submarines was located and recovered from Pearl Harbor. Possibly, this torpedo was fired by this midget submarine.

Shipwreck
After the West Loch explosion on May 21, 1944 the U.S. Navy (USN) was salvaging wreckage from the explosion and discovered and raised to the surface this midget submarine. Both torpedo tubes were empty indicating both torpedoes were fired. Afterwards, this midget submarine dumped into the sea three miles south of Pearl Harbor. Until 1960, the discovery of this midget submarine remained classified.

During 2009, the dumped midget submarine was rediscovered by a team assembled by PBS Nova positively identified as "Midget E" (M-16), the last of the five midget submarines used at Pearl Harbor.

Memorial
On March 6, 1942, the midget submarine crews of all the Pearl Harbor attack (except Ensign Sakamaki who was known to have become a Prisoner Of War) were each posthumously promoted two ranks. The crews are also memorialized at the Nine War Gods Monument at Suga Park bordering Mitsukue Bay in Ehime Prefecture.

References
Combined Fleet - Midget Submarines at Pearl Harbor, Hawaii 1941
Combined Fleet - HIJMS Submarine I-16: Tabular Record of Movement
US Navy Heritage - Japanese Navy Ships -- Ha-19 (Midget Submarine, 1938-1941)
HURL "Report on Condition of 3 Piece Japanese Midget Submarine by Terry Kerby pages 1-17
NOVA "Pearl Harbor Sub Discovered" December 7, 2009
NOVA "Killer Subs in Pearl Harbor" first aired May 23, 2012
I-16tou.com details the discovery of this submarine

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Last Updated
August 4, 2020