Advanced SEAL Delivery System

Advanced SEAL Delivery Systems (ASDS) are midget submarines operated by the United States Navy and SOCOM, designed to provide stealthy submerged transportation for special forces, primarily U.S. Navy SEALs, from the decks of nuclear submarines.

ASDS are some 65 feet (20 meters) long, displace about 60 tons, and are operated by a crew of two. Battery propelled, they have a range of about 200 kilometers, a top speed of some 7.5 knots (14 kilometers an hour) and an operating depth of 200 feet (61 meters). They can carry up to 14 passengers with little equipment or eight with a standard load-out. They are equipped with passive and active sonar, radar, and a photonics mast. They cost some US$300 million.