USS Dolphin ( AGSS - 555 ) USS " Dolphin " ( AGSS - 555 ) was the United States Navy ' s last operational diesel - electric , deep - diving , research and development submarine . Her keel was laid down on 9 November 1962 at the Portsmouth Navy Yard , Kittery , Maine . She was launched on 8 June 1968 sponsored by Mrs . Daniel K . Inouye ( the wife of the senator for Hawaii ) , and commissioned on 17 August 1968 with Lieutenant Commander J . R . McDonnell in command . Despite her recent repair and upgrade , " Dolphin " was decommissioned on 15 January 2007 and was struck from the Naval Vessel Register on the same date . She is now a museum ship in San Diego Bay under the management of the San Diego Maritime Museum . Design . The single most significant technical achievement in the development of " Dolphin " is the pressure hull itself . It is a constant diameter cylinder , closed at its ends with hemispherical heads , and utilizes deep frames instead of bulkheads . The entire design of the pressure hull has been kept as simple as possible to facilitate its use in structural experiments and trials . Hull openings have been minimized for structural strength and minimum hull weight , in addition to eliminating possible sources for flooding casualties . The submarine has no snorkel mast ; her one hatch must be open while her diesels are running . Use . Employed by both civilian and Navy activities , " Dolphin " is equipped with an extensive instrumentation suite that supports missions such as acoustic deep - water and littoral research , near - bottom and ocean surveys , weapons launches , sensor trials , and engineering evaluations . Because she was designed as a test platform , " Dolphin " can be modified both internally and externally to allow installation of up to 12 tons of special research and test equipment . The submarine has internal and external mounting points , multiple electronic hull connectors , and up to ten equipment racks for project use . Service record . In August 1969 , " Dolphin " launched a torpedo from the deepest depth that one has ever been fired . Other examples of " Dolphin " ' s work include " Dolphin " was overhauled in 1993 . In the late 1990s , " Dolphin " tested a new sonar system . As a result of " Dolphin " ' s efforts , this new system will now be retrofitted into the fleet . Abandonment at Sea Incident . On 21 May 2002 , at about 1130 PDT , while operating approximately off the coast of San Diego , California , " Dolphin " was cruising on the surface , recharging its batteries , when a torpedo shield door gasket failed , and the boat began to flood . Due to high winds and swells in the ocean , approximately 70 to 85 tons of seawater entered the ship , an amount perilously close to the boat ' s reserve buoyancy . The flooding shorted electrical panels and started fires . Chief Machinist ' s Mate ( SS ) John D . Wise Jr . , realizing what needed to be done , dove into the water of the flooded pump room . Not knowing if the room ' s equipment had been secured , and with less than a foot of breathable space in the compartment , he ensured the seawater valves were lined up , allowing the de - watering to commence . Once the valves were aligned , he remained in the pump room for more than 90 minutes in order to keep a submersible pump from becoming clogged . His courageous efforts prevented the loss of the ship and crew . Wise received the Navy and Marine Corps Medal for his efforts . After 90 minutes , Commander Stephen Kelety , " Dolphin " ' s commanding officer , ordered the crew of 41 and two civilian Navy employees to abandon ship . The Oceanographic Research ship " McGaw " was operating in the vicinity and immediately responded . The fire and flooding was beyond the ability of the crew to control so they were evacuated by small boat to " McGaw " after the submarine hatches had been secured . All crewmembers were safely recovered with only a few minor injuries . Two crewmembers were recovered from the water by United States Coast Guard helicopter during the transfer . " McGaw " transported the crew to San Diego . The quick response of the crew placed the submarine in a stable condition . came alongside " Dolphin " and rescued several crewman from the water but the seas were too rough for full recovery or towing operations . Submarine Support Vessel " Kellie Chouest " got underway from San Diego early on 22 May to assist in the recovery assessment . " Dolphin " was towed back to San Diego the following day . The last time an American submarine caught fire and was abandoned was in 1988 , when the diesel sub lost three sailors in a battery compartment fire . Retirement . " Dolphin " underwent three and a half years of repairs and upgrades at a cost of $ 50 million , then completed sea - trials during the summer of 2005 and returned to her duties for one year . In mid - 2006 , the Navy decided to retire " Dolphin " , citing the $ 18 million her operations cost annually . She was deactivated on 22 September 2006 , and decommissioned and struck from the Naval Vessel Register on 15 January 2007 . ex - " Dolphin " was officially transferred to the San Diego Maritime Museum in September 2008 , to become the eighth vessel in their floating collection . She was opened to the public for the first time on 4 July 2009 .