The SEAL Delivery Vehicle (SDV), also known as Swimmer Delivery Vehicle, is a crewed submersible and a type of swimmer delivery vehicle used to deliver United States Navy SEALs and their equipment for special operations missions. It is operated by SEAL Delivery Vehicle Teams.

The SDV, which has been in continuous service since 1983, is used primarily for covert or clandestine missions to denied access areas (either held by hostile forces or where military activity would draw notice and objection). It is generally deployed from the Dry Deck Shelter on a specially-modified attack or ballistic missile submarines, although it can also be launched from surface ships or land. It has seen combat in the Gulf War, Iraq War, and the US intervention in Somalia.

The SDV was intended to be replaced with the Advanced SEAL Delivery System (ASDS), a larger, dry submersible that is often confused with the SDV. The SDV is flooded, and the swimmers ride exposed to the water, breathing from the vehicle's compressed air supply or using their own SCUBA gear, while the ASDS is dry inside and equipped with a full life support and air conditioning system. The ASDS was canceled in 2009 due to cost overruns and the loss of the prototype in a fire. The Navy currently plans to replace the SDV with the Shallow Water Combat Submersible (SWCS), which will be designated the Mark 11 SDV.

The same capability was adopted by the American Underwater Demolition Teams (UDTs) in 1947. The one-man submersible displayed little functional military potential. However, it substantiated and characterized the need for improved and expanded UDT capabilities. After the war, development continued in a garage-shop fashion by various UDT units, and included various "Marks" such as the Mark V, VI, and VII. Intermediate numbers were assigned to some vehicles that never made it off the shop floor. All were of flooded design.

The first SDV to be operationally deployed was the Mark VII, which entered service in June 1972 after being tested between 1967 and 1972. Finally, the SDV can be launched from the shore. Another advantage of the Mark 8 Mod 1 over its predecessor is that it is built from aluminium instead of plastic reinforced fiberglass, making its hull sturdier and roomier. These torpedoes can travel up to in a straight line, In addition to torpedoes, the Mark 9 also carried limpet mines and satchel charges in a large cargo compartment aft of the pilot and co-pilot. The Mark 9 SDV was intended to attack ships in shallow coastal waters that full-size submarines could not enter, although SEALs reported that staying prone for the entire duration of an operation was uncomfortable. It has been invaluable at deploying SEAL teams in clandestine missions, as it has enabled them to land on shores inaccessible to a larger submarine with a degree of stealth greater than that offered by small surface craft, helicopters, or other means. In exercises, the SDV has been found to excel at anti-shipping attacks, being able to attack targets in heavily-guarded fleets or docked at military bases and then slip away undetected. Additionally, it can carry larger limpet mines than those carried by a diver and has a much greater range than a diver, enabling attacks on larger and more distant enemy ships. On March 20, 2003, SEALs from SEAL Team 8 and 10 (31 SEALs, 2 Navy EOD, 1 USAF combat controller, and several Iraqi interpreters) moved to seize the MABOT oil terminal and KAAOT Oil Terminals, in part using SDVs. The terminals were quickly seized with no casualties, and explosives which were found on the terminals were made safe by Polish GROM operators.

In 2003, SEALs using SEAL Delivery Vehicles swam ashore along the Somali coastline and emplaced covert surveillance cameras. Known as cardinals, the cameras were designed to watch likely target locations for wanted terrorists as al-Qaeda and its affiliates began to regroup in the country, however the cameras only took one image a day and captured very little.

In American service, the SDV is deployed with SEAL Delivery Vehicle Team 1 (SDVT-1), based in Pearl Harbor, and SEAL Delivery Vehicle Team 2 (SDVT-2), based in Little Creek, Virginia. SDVT-1 operates on behalf of Central Command and Pacific Command in the Middle East and Indian and Pacific Oceans. SDVT-2 operates in the Atlantic and European Command and Southern Command, and is primarily focused on supporting the activities of the Sixth Fleet.

Operators

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  • United States Navy: Navy SEALs
  • SEAL Delivery Vehicle Team 1 (SDVT-1)
  • SEAL Delivery Vehicle Team 2 (SDVT-2)

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  • Royal Navy: Special Boat Service

<gallery widths="225px" heights="165px" class="center">

File:SEAL Delivery Team operations.jpg|A Navy diver and special operator from SEAL Delivery Team 2 operate an SDV from the nuclear-powered guided-missile submarine

File:SEAL Delivery Vehicle loading.jpg|An SDV being loaded aboard Los Angeles-class attack submarine

File:SDVmk9 LittleBoPeep.jpg|Mark 9 SDV "Little Bo Peep" armed with a LAM-5 mine

File:US Navy 050505-N-3093M-003 A member of SEAL Delivery Vehicle Team Two (SDVT-2) prepares to launch one of the team's SEAL Delivery Vehicles (SDV) from the back of the Los Angeles-class attack submarine USS Philadelphia (SSN 690).jpg|A member of SEAL Delivery Vehicle Team Two (SDVT-2) prepares to launch a Mark 8 SDV from Los Angeles-class attack submarine

</gallery>

See also

  • Chariot manned torpedo
  • Human torpedo

References

  • Video of a SEAL Delivery Vehicle in use
  • Military.com article
  • USS Nautilus Museum exhibit