MISSING FIFTH MIDGET SUBMARINE FOUND?
All three sections discussed and pictured above when discovered by HURL in 1992, 2000 and 2001 were found to have been disconnected at the joining sections, had rigging cables attached and had been scuttled. An approximately 15-foot piece of this midget submarine’s aft mid-section, as shown on the drawing below, is still missing. This piece is from the jagged end where a scuttling charge blew the stern off, to where the bolts of the intact part of the stern section were later cut off with a torch or saw.
The origin of the three sections of the midget submarine is unknown, but Terry Kerby, HURL's Director of Operations, has developed a theory that makes sense. His theory centers on “The Second Pearl Harbor Disaster” discussed above. Kerby believes the three pieces were discovered during clean up of West Loch. The civilan salvors probably lifted the two main pieces of the hull onto a crane barge and disassembled it at its flange joints to make it easier for disposal. Later, the three pieces were dumped in the Defensive Sea Area, along with other debris from West Loch.HURL's investgators verified that the submarine pieces had been disassembled and rigged with cables for easier handling. The West Loch Disaster was placed under a veil of secrecy, so there was no record of the salvage and disposal.As noted above, the torpedo tubes in the bow-section of the Type A midget submarine found on 29 August 2001 were empty. HURL's theory is that this midget fired its torpedoes at Captain (Rear Admiral-Ret) George A. Rood's USS ST. LOUIS (CA-49) as she exited South Channel out of Pearl Harbor at 22 knots. Both torpedoes missed and exploded on the reef.Finally, Rear Admiral Ueda Kazuo (JMSDF-Ret)(a midget submarine commander and ex-staff member of the Japanese Midget Submarine Association) confirmed that only the Pearl Harbor midgets had the "figure 8" net guard/cutter over the torpedo tubes. Thus, there is strong evidence that the three pieces discovered in the Defensive Sea Area comprise the missing fifth midget submarine. It is thought by some researchers to be Yokoyama and Ueda's M-16, however, this identification is also speculative.Many thanks go to Steven L. Price of the Hawaii Undersea Research Laboratory for assistance with this revision.
27 July 1992:A team from the University of Hawaii’s Undersea Research Laboratory (HURL), in the deep-submersible vehicle PISCES V locates the aft section of a Type A midget submarine 1200 feet down in the Defensive Sea Area several miles off Pearl. Postwar, this area became a dumping ground for hundreds of items of obsolete or discarded war materials, such as landing craft, tanks, old aircraft, trucks, barges, small ships, fuel tanks etc. The aft section is located in this field with other debris. Unfortunately, PISCES V’s tracking system is malfunctioning and cannot provide reliable coordinates to the surface. As a result, the location of the aft section of this Type A is temporarily “lost”.
5 September 2000:PISCES V locates the mid-section of a Type A midget submarine at 1200 feet in the Defensive Area. The mid-section is missing about 15 feet aft of the conning tower, possibly caused by the submarine’s scuttling charges. A survey of this section indicates that it most probably was dumped here. 
9 November 2000:Famed Wood’s Hole Oceanographer and undersea explorer Bob Ballard’s deep-water remote-operated imaging vehicle ARGUS lights up the remains of a Type A midget submarine in the Defensive Area dumping ground. Only its mid-section and sail remains. This mid-section is the same one HURL found two months earlier. It is theorized that this midget submarine had been captured in another campaign, possibly Guam, studied by intelligence experts at Pearl, then dumped. 
29 August 2001:PISCES IV is enroute to the mid section discovered the previous fall when the dive team locates the bow-section of a Type A midget submarine at 1200 feet. The bow is fitted with an early “figure 8” net guard/cutter. The torpedo tubes are empty. A hole has been punched in forward part of this bow section to allow a hawser to be attached to drag and dump the section into the Defensive Area. After filming these two sections the team continues exploring and "rediscovers" the tail section found nine years earlier.