Near the end of WW II Pampanito underwent her first major ship yard refit and overhaul at Hunters Point Naval Shipyard in San Francisco following six war patrols. The modifications made at that time included the installation of a new type of radar (SV), main deck gun and ammunition scuttle, and the submarine was drydocked to prepare her for her seventh patrol. On the way to Pearl Harbor to start the patrol, the war ended and Pampanito returned to the Bay Area. In December she was decommissioned and laid up in reserve in December, 1945 at Mare Island Naval Shipyard with about fifty other submarines. At that point, the Navy had every intention of possibly returning Pampanito to service, and she was maintained as such.
By the early sixties the submarine was considered obsolete as a deployable asset and was transferred to the Naval Reserves to use as a training platform. During this period modifications were made to Pampanito so that diving and surfacing simulations could be made. Some of the original equipment was removed or modified, although she remained in her WW II configuration and was not modified to be put back into active service. Following her training mission the submarine was stricken from the Navy and she was scheduled for disposal. In 1970 she was made available for industrial stripping and several key pieces of equipment were removed to meet the needs of the fleet. There were still some WW II diesel boats in service, mostly GUPPY conversions being sold to foreign countries. All of the spare parts located in her lockers were removed, but fortunately the removal of equipment was kept to a minimum because Pampanito, in good material condition and was considered to be a candidate for being developed as a museum ship.
When the Maritime Park Association looked at the available submarines at Mare Island to choose one for exhibit, Pampanito was picked because of her good condition and largely unmodified configuration. In preparing the submarine for display she was again modified as visitor access ladders and handrails were added. The difference with these modifications was that they were made with the possibility of undoing what was done. The torpedo loading hatches that were removed to allow visitor ladders into the torpedo rooms were retained and put into storage so that they could be replaced if desired at some time in the future.
From the time Pampanito was opened to the public in 1982, a process has been underway to return the submarine to her appearance and condition as it was the moment she left Hunters Point in 1945 to represent the height of WW II submarine development. The Association has searched the country looking for missing equipment and spare parts. Today Pampanito has had the bulk of these missing items replaced and again has some spare parts in her lockers. Much of the equipment has been restored to operational condition. The wish list of needed items gradually got smaller as Pampanito went backwards in time to her most significant period, World War II. We are very thankful to the many individuals, companies and government agencies that have helped us replace the missing equipment.
Current projects include work on the hydraulic systems, trim and drain systems and loading the forward torpedo room with torpedoes and skids. Almost all of this work has been done without outside funding. We are also working on the navigation and fire control systems.
The restoration projects have been numerous and ongoing since 1982. Every work item done to Pampanito has been recorded and the book that lists them all is now over 300 pages and growing. Some of the many elements that have enabled these projects are are listed below.