Four points in time show the I-16tou's position and intentions:
Nothing more would be heard from I-16tou until 2241 Honolulu time, when Kichiji Dewa aboard mother sub I-16 would receive a brief signal from Sub-Lieutenant Masaharu Yokoyama. "Attack successful," was the last word ever heard from I-16tou.
Pearl Harbor submarine historian Ray de Yarmin says the night message not only came from Yokoyama aboard I-16tou, but that it was transmitted from inside the harbor! I-68 and I-69, he adds, were ordered to loiter at the harbor entrance to rescue Yokoyama.
- Burl Burlingame, Advance Force Pearl Harbor, pg. 432
What were the I-16tou's options at this point? The anti-torpedo net was closed at the entrance. They may or may not have realized that they had come under fire from Bobolink. Destroyers were passing overhead of them as they were exiting. CO2 content within the midget submarine problem would soon reach toxic levels. A careful turn into the West Loch would have placed them out of harm's way and out of sight of American units. The first isolated area in the West Loch they would have come to would have been Walker's Bay, an isolated area with no facilities or prying eyes. Here they could have waited until nightfall so that they could take advantage of the darkness to recover from their O2/CO2 problem and maybe even gone ashore on the Waipio peninsula in order to conspicuously conduct a battle damage assessment of the attack on Pearl Harbor. After radioing their signal, the crew would have scuttled the I-16tou and have made their way to a designated safe house in Pearl City.
An Evasion and Escape chart was recovered from the captured I-24tou, which displayed key features around Oahu and Pearl City and a location for the submarine crew to head for in case they had to abandon their submarine and make their way ashore. This location was the house of Doctor Yokichi Uyehara, located at a waterfront home on Pearl City peninsula and looking directly out onto Pearl Harbor's Middle Loch.
"[Doctor] Uyehara's brother Shinko was a lieutenant and surgeon in the Imperial Navy, coincidentally stationed at the Naval Torpedo School in Yokosuka, home base of the midget submariners."
- Burl Burlingame, Advance Force Pearl Harbor, pg. 122
Walker Bay was directly across the West Loch from Naval Ammunition Depot Lualualei. During the war, Landing Ship, Tanks (LST) would nest at the mouth of Walker Bay to take on ammunition from the depot for the Pacific Island invasion campaigns.
I-16tou had been missing from history for nearly sixty years before being discovered in pieces between 1992 and 2001 by Hawai'i Undersea Research Laboratory (HURL) Chief Pilot Terry Kerby. Attempts to convince the public that he had discovered a Pearl Harbor midget submarine was hindered by assumptions that the wreck was a discarded war trophy from Guadalcanal. Through the efforts of an experienced and bi-national team of historians and explorers, brought together in 2009 by the Lone Wolf Documentary Group, Terry Kerby's discovery has now been brought to light and placed in its proper historical context.
The wreck of I-16tou is currently located in the Submarine Restricted Zone outside the Pearl Harbor channel. Its three sections lay in a line and each are wrapped in cable hawsers used to raise the submarine pieces and dump them in their present location. This means that the United States Navy had previously located the I-16tou and relocated her. Salvage reports during both the war and post-war periods show no salvage efforts were ever made outside of Pearl Harbor. This is a clear indication that the I-16tou was located within Pearl Harbor, but where? The answer lies with the wreck itself and the area around the wreck on the ocean floor. Along the line of the three pieces of the midget submarine are several Marine Landing Vehicle Tracked (LVT) amphibious vehicles utilized by United States Marine amphibious forces to invade Japanese-held islands throughout the Pacific. These LVTs were dumped here as a result of a clean-up effort from the West Loch disaster which occurred in Walker Bay inside the West Loch of Pearl Harbor on 21 May, 1944. Preparing for the upcoming invasion of Saipan, six Landing Ship Tank (LSTs) and three Landing Craft Tank (LCTs) were destroyed. 163 men died in the explosions and 396 more were wounded. It was during this clean-up effort – classified Top Secret due to the need to keep the invasion preparations from the enemy – that the I-16tou was located by salvage crews.