Advanced SEAL Delivery System Advanced SEAL Delivery System ( ASDS ) was a midget submarine operated by the United States Navy and United States Special Operations Command designed to provide stealthy submerged transportation for special operations forces ( primarily United States Navy SEALs ) from the decks of nuclear submarine s for primary use as an insertion platform for covert and clandestine operation s . The program was abandoned after the only prototype example of the class was damaged beyond economic repair in an accidental fire . Missions . ASDS was conceived to address the need for stealthy long - range insertion of special operations forces on covert or clandestine missions . Previous mini - subs were of the wet variety , exposing combat Swimmers to long , cold waits during transit that impeded combat readiness on arrival , and had limited blind underwater navigational capability . Development . The first study to define ASDS was performed in 1983 . Competitive conceptual designs were developed in the late 1980s , the Request for Proposal was issued in 1993 , and the first contract for design and construction of the ASDS was awarded in 1994 . The navy has stated a requirement for six units , but that was established before it decided to convert four Ohio - class ballistic - missile submarines to guided - missile submarines ( SSGNs ) with the additional mission of support of special operations forces . Each of the SSGNs will be capable of carrying two ASDS vehicles . The first ASDS became operational ( completed testing and evaluation ) from its base at Pearl Harbor , Hawaii , in 2003 and completed its first deployment on board an attack submarine , the USS " Greeneville " , to the Indian Ocean and Persian Gulf as a unit of Expeditionary Strike Group One . The first ASDS has yet to be joined by other units , as the program has been slowed by escalating costs and technical problems . A Congressional Budget Office ( CBO ) study issued in 2003 cited two major technical problems : noisy propellers and silver - zinc batteries that depleted more quickly than planned . A new propeller made of composite material has been developed to rectify the noise problem . Development is under way on lithium - ion batteries to replace the silver - zinc batteries and enable the electrical system to meet the navy ' s requirements . Yardney Technical Products of Pawcatuck , Conn . , has been awarded a $ 44 million contract modification to provide four lithium - ion batteries for the ASDS program by May 2009 . In the end , however , technical , reliability , and cost issues have proven nearly insurmountable . Indeed , the ASDS has been cancelled for all intents and purposes ; all that ' s left is an ASDS - 1 improvement program to boost the performance of the existing sub and complete its operational testing . The Richmond Times - Dispatch notes that the ASDS mini - subs were originally supposed to cost $ 80 million each , but numerous problems with the first boat have ballooned its cost to $ 446 million so far ( vendor and government facility costs inclusive ) . Instead of completing integration and entering service in 2000 , testing continued and the first boat was officially delivered in July 2003 . GlobalSecurity adds that the program was initially projected to cost $ 527 million ( including delivery of all six boats ) , but it is now predicted to rise to more than $ 2 billion – significantly more than the $ 1 . 4 billion SSGN Tactical Trident conversion program to which it is related . Funding was provided via Congressional line item to the Special Operations Command . The Navy Deep Submergence Office was selected as the technical design agent and program office . Technical assistance was provided by the Navy Experimental Dive Unit , Panama City ; the Naval Special Warfare Command , Coronado ; SEAL Delivery Vehicle Team 2 , Norfolk ; and the Special Operations Command ( SOCOM ) Special Operations and Acquisition Logistics ( SOAL ) , Tampa . Detailed design of the first ASDS was started in 1994 , and hull construction undertaken in 1996 , at a government estimated cost of US $ 160 million , to a low bid for the delivery of $ 69 million for the first ASDS ( to include non - recurring design costs , fabrication , and testing ) , and subsequent copies for $ 25 million each . It was delivered for testing and evaluation in 2000 and cost US $ 300 million ( vendor and program office costs inclusive ) to develop . Subsequent submarines were estimated to cost $ 125 million ( based on a 2001 estimate ) a copy . Five more were planned , but production of the second system was placed on indefinite hold in December 2005 pending a production and cost review , and the resolution of many reliability problems ( primarily wiring grounds ) . Cancellation . In April 2006 , the program for new submarines was canceled and Northrop Grumman notified of termination . The current submarine was still in development and use until damaged in a " serious fire " in November 2008 . As of December 2008 the cause of the fire is yet to be determined . Given the probable extent of fire and water damage ( the mini - sub burned for six hours and remained sealed for two weeks ) it was highly unlikely that the craft could be saved . On 24 July 2009 , US Special Operations Command ( USSOCOM ) announced that the ASDS was not going to be repaired . Follow on programs . The Joint Multi - Mission Submersible follow - on program was abandoned in 2010 over cost concerns , in favor of Commercial off - the - shelf platforms . Critical Design Challenges . Power – The long range requirement strained the ability of existing battery technology . Shock – Shock requirements for the vessel and for equipment mounted inside translated to " g " acceleration forces four times that currently specified for fleet nuclear submarines . No existing submarine equipment of any kind existed that survived the shock . Displays , computers , mountings , and life support equipment were expensive to re - engineer . Host Needs – Weight , size , and center of gravity all were limited by what could be carried on the back of a 688 class submarine . Life Support – The large number of passengers for the small submarine , the need for fully automated and self - controlling systems , and the long periods of submersion ( days ) presented serious challenges that could not be met with Commercial Off The Shelf ( COTS ) nor Government Off The Shelf ( GOTS ) systems . Existing systems used on large submarines required too much space and too much power . Existing systems on small submarines lacked capacity and the ease - of - use required for combat . Internal heating and cooling systems not usually needed for large submarines were needed for the smaller sub that would go into shallower warmer waters or colder surface waters . Navigation – Sonar systems developed for attack submarines , but needed for the shallow water maneuvers , were large , power hungry , and gave off lots of heat . Construction – Initial designs and bids were based on standard submersible construction . During later design phases the government imposed full nuclear sub shock , hull and piping requirements on the designers – nullifying the " off the shelf " design approaches requested by the government in earlier phases . To accommodate the larger piping and thicker hull , other systems had to be lightened . ( Reference the GAO and RAND reports . ) Capabilities . Two Los Angeles class submarine s have been modified to deploy the ASDS , and the new Virginia class submarine is being built with the inherent capability to deploy the mini - sub . Planners originally intended the ASDS to be piloted by one submarine officer and one SEAL . This occurred during initial testing and operational evaluation . However , so far , the first ASDS has been operationally piloted by two submarine officers . The sub was designed to carry 16 SEALs in addition to the two pilots . Smaller swimmer propulsion devices such as the STD ( Swimmer Transport Device ) may be carried internally ( basically smaller scooters ) , and small Combat Rubber Raiding Craft ( CRRC ) or Inflatable Boat - Small ( IBS ) may be stored internally . However , such craft cannot carry gasoline engines due to safety issues on submarines and fuel issues in small spaces , and therefore have to be paddled or use small electric motors . Semi - rigid , rigid hull , and rigid - hulled inflatable craft such as the ZODIAC cannot be accommodated .