In a program that began with great promise but soon spiraled out of control, Northrop Grumman has been building the ASDS “Advanced SEAL delivery System” mini-subs, the successors to the previous SDV (SEAL/Swimmer Delivery Vehicle) carried on US Benjamin Franklin Class (SSBN-640) attack submarines.
Unlike the SDV, which is flooded and requires SCUBA gear, the 16 Navy Seals, MARSOC, or other covert action personnel in an ASDS can arrive at their mission drier, warmer, and less fatigued. The ASDS can be launched from the converted SSGN Ohio Class Special Ops/Land Strike submarines, and also from Virginia Class (SSN-744) submarines, from the improved Los Angeles Class (SSN-688I) subs Charlotte (SSN 766) and Greeneville (SSN 772), or from the well decks of amphibious assault ships like the LHD Wasp Class or LPD-17 San Antonio Class. The new mini-sub also fits in a C-17 Globemaster or C-5 Galaxy aircraft for rapid transport to an appropriate launch platform.