USS Idaho (SSN-799) Submarine

Full Specifications

USS Idaho (SSN-799): Virginia-Class Block IV Attack Submarine

The USS Idaho submarine represents the cutting edge of American undersea warfare as the 26th Virginia-class nuclear-powered fast-attack submarine and the eighth in the Block IV configuration. Commissioned on April 25, 2026, at Naval Submarine Base New London, this vessel brings enhanced warfighting capabilities designed to maintain U.S. naval superiority in contested waters. Optimized for anti-submarine warfare, anti-surface warfare, intelligence gathering, surveillance, and special operations support, the Idaho excels in both open-ocean and littoral environments.

Manufacturer

USS Idaho submarine was built under a teaming arrangement between General Dynamics Electric Boat (primary builder for this hull) and Huntington Ingalls Industries Newport News Shipbuilding. It is the 14th Virginia-class submarine delivered by Electric Boat.

Speed and Range

Powered by the S9G nuclear reactor, the submarine achieves speeds exceeding 25 knots submerged. Its nuclear propulsion provides virtually unlimited range, limited only by crew provisions and maintenance cycles, enabling extended patrols of up to three months submerged.

Cost/Price The projected unit cost for USS Idaho is approximately $2.6 billion. Block IV submarines incorporate design improvements focused on reducing total ownership costs and increasing the interval between major maintenance availabilities, enhancing fleet readiness.

Major Capabilities

The Idaho features a streamlined hull measuring 377 feet in length with a 34-foot beam and submerged displacement of approximately 7,800–7,900 tons. It is equipped with four 21-inch torpedo tubes capable of launching Mk 48 ADCAP heavyweight torpedoes and mines, plus 12 vertical launch system (VLS) tubes or Virginia Payload Tubes for Tomahawk cruise missiles (and potentially Harpoon anti-ship missiles). Advanced sensors include a large spherical sonar array, wide-aperture flank arrays, high-frequency active sonars, and photonic masts replacing traditional periscopes. Stealth is achieved through anechoic coatings, noise-reducing features, and a pump-jet propulsor that minimizes acoustic signature.

Block IV improvements emphasize reliability and reduced lifecycle costs while retaining the class’s hallmark flexibility, including reconfigurable spaces for special operations forces such as Navy SEAL teams and potential unmanned underwater vehicle (UUV) integration.