SDV Unit Profile

[SR-25]

Although SEALs are adept at ingressing to a target via long-range swims, there are times when the mission dictates other methods. When the mission dictates longer distances than a SEAL can swim and still be effective, or when more gear is needed than they can tow in, SEAL Delivery Vehicles (SDVs) are required. SDVs transport the SEALs and their gear from an offshore point such as a submarine to points near the shore, at which point they leave the vehicle and swim the rest of the way in. During some missions, such as the mining of ships in enemy harbors, they may hardly leave the craft at all.

The SDV provides life support for the embarked SEALs. The earlier boats allow each SEAL to plug into an onboard air source and are flooded during operations, but the new Advanced SEAL Delivery System carries the SEALs in a dry compartment, keeping them warmer longer and increasing their effectiveness once they reach their drop off point. Each type of SDV is powered by batteries and offers navigation and communications equipment in addition to the propulsion and life-support systems.

The main SDV used by SEALs currently is the Mk XIII Mod 1, which is twenty-two feat long and is rated to carry six SEALs (two operators and four passengers). It can travel at about six knots out to a range of about seventy miles, although in many cases the effects of water conditions on the crew is more of a limitation than the battery power. The Mk IX SDV was developed to carry a crew of two SEALs and two Mk 37 torpedos for use in stand off attacks against enemy shipping but has been superceeded by the revised Mk VIII boat. The latest addition to the delivery vehicles is the new ASDS system.