SEAL Delivery Vehicle

SEAL Delivery Vehicle
Name	SEAL Delivery Vehicle
Caption	submersible used by United States Navy SEALs
Country	United States
Type	midget submarine
Builder	Electric Boat Division, General Dynamics; Lockheed Martin; other contractors
In service	1960s–present
Complement	Typically 2–6
Displacement	variable
Length	variable
Propulsion	electric battery; shore battery charging; some wet sub designs

SEAL Delivery Vehicle The SEAL Delivery Vehicle is a crewed submersible developed to transport United States Navy Navy SEALs and special operations personnel covertly from ships, submarines, or shore to maritime objective areas. It evolved alongside programs in Underwater Demolition Team operations, Special Warfare Command requirements, and advances in submarine and diver technology, forming part of a family of midget submarines and swimmer delivery systems used in littoral and denied environments.

History

The concept traces to early World War II swimmer delivery efforts such as Italian Decima Flottiglia MAS operations and British Special Boat Service experiments; postwar US efforts accelerated with Underwater Demolition Team experience in the Korean War and Vietnam War. During the 1960s the Naval Special Warfare Command contracted industrial firms including General Dynamics and later Lockheed Martin to produce purpose-built delivery vehicles for SEAL Team infiltration missions and intelligence collection. Cold War exigencies and operations in the Mediterranean Sea, Persian Gulf, and South China Sea shaped requirements, leading to iterative upgrades tied to OHIO-class submarine dry deck shelter integration and cooperative programs with allied services such as the Royal Navy and Special Air Service maritime elements.

Design and Technical Characteristics

SEAL Delivery Vehicles are midget submersibles or wet submersibles designed for low observability and swimmer carriage. Early platforms emphasized battery-electric propulsion, low magnetic and acoustic signatures to counter anti-submarine warfare sensors developed by NATO and Warsaw Pact navies. Hulls used pressure-tolerant materials and hydrodynamic forms informed by hydrofoil and submarine hull research; life-support systems incorporated closed-circuit rebreathers derived from combat diver technology and standards set by Naval Medical Research Command. Navigation suites combined inertial navigation systems influenced by Inertial Measurement Unit advances, Doppler sonars, and periscope alternatives adapted from attack submarine sensor arrays. Integration with dry deck shelters allowed compatibility with Los Angeles-class submarine and other host platforms, while appendages and clamps were adapted for carriage by surface ship davit systems and submarine rescue interfaces.

Operational Use and Units

SEAL Delivery Vehicles have been operated primarily by United States Navy SEAL Team One, SEAL Team Two, Naval Special Warfare Group One, Naval Special Warfare Group Two, and specialized platoons within Special Boat Teams and Naval Special Warfare Development Group. Missions have included covert insertion and extraction, reconnaissance for amphibious assault operations, limpet mine delivery in countershipping strikes, and over-the-horizon beach reconnaissance supporting Marine Expeditionary Unit operations. Allied units such as elements of the Royal Navy's Special Boat Service and select Special Operations Command partners have employed comparable systems in multinational exercises like RIMPAC and bilateral training with United States Indo-Pacific Command.

Training and Deployment Procedures

Training pipelines for SDV operators draw from BUD/S graduates who proceed to SDV-specific courses at Naval Special Warfare Center detachments and specialized training facilities. Curriculum covers navigation using sonar and inertial systems, emergency protocols aligned with Navy Diving and Salvage standards, battery and electrical maintenance, and tactical employment in cooperation with submarine crews for dry deck shelter operations. Deployment procedures include embarkation aboard host submarines or surface ships, pre-mission briefings coordinated with intelligence and command and control elements, and contingency plans referencing Search and Rescue and submarine escape doctrines.

Variants and Development Programs

Over decades multiple variants and development programs emerged, including early wet submersibles and later air-independent or dry sub designs pursued under competitive contracts from firms such as Lockheed Martin, General Dynamics Electric Boat, and smaller defense contractors. Notable programs interfaced with Los Angeles-class submarine dry deck shelter (DDS) integration and explored greater range, payload, and crew endurance to meet requirements articulated by Naval Special Warfare Command and United States Special Operations Command. Internationally, comparable programs influenced and were influenced by projects from the Royal Navy, French Navy special forces, and Israeli Navy frogman units, leading to cross-service technology sharing and export considerations managed under International Traffic in Arms Regulations.

Incidents and Losses

Operational history includes accidents and losses tied to challenging operating envelopes, such as mishaps during training involving battery fires, flooding, and entanglement, prompting investigations by Naval Safety Center and Navy Inspector General. High-profile incidents influenced procedural and design changes similar to reforms that followed other naval accidents investigated by Joint Chiefs of Staff-level review boards. Lessons learned contributed to improved escape protocols, stricter maintenance regimens, and tighter integration with host submarine safety systems.

Category:Submersibles Category:United States Navy special operations