USS Idaho (SSN-799)

History

USS Idaho (SSN-799) is a U.S. Navy Virginia-class nuclear-powered fast-attack submarine and the eighth boat of the Block IV configuration. It is the 26th Virginia-class submarine and the fifth U.S. Navy vessel named for the state of Idaho.

Idaho was built under the Virginia-class teaming arrangement between General Dynamics Electric Boat and HII Newport News Shipbuilding. The submarine was commissioned on 25 April 2026 and entered its first overseas operational deployment less than six months later.

Block IV Virginia-class submarines were designed to improve operational availability by reducing major maintenance periods over their service lives and increasing the planned number of deployments.

Construction and commissioning

The name Idaho was announced in August 2015. The submarine was ordered as part of the Virginia-class construction program and its keel-laying ceremony took place on 24 August 2020 at the General Dynamics Electric Boat Quonset Point facility in Rhode Island.

Idaho was christened on 16 March 2024 at the Electric Boat shipyard in Groton, Connecticut, with Teresa Stackley serving as sponsor. The submarine was launched on 6 August 2024. The 16 March 2024 date refers to the christening rather than commissioning; USS Idaho formally entered U.S. Navy service on 25 April 2026 at Naval Submarine Base New London.

At commissioning, Idaho became the 26th Virginia-class submarine and the eighth Block IV boat. Cmdr. Chad J. Guillerault served as commanding officer.

Design

USS Idaho is a Block IV Virginia-class nuclear-powered attack submarine intended for missions including anti-submarine warfare, surveillance, strike operations, and other undersea missions. Its nuclear propulsion plant is designed to operate for the planned life of the submarine without reactor refueling.

Hull and propulsion

The submarine is approximately 115 m long and 10.4 m in beam, with a submerged displacement of about 7,800 tons. Nuclear propulsion provides long underwater endurance without the fuel limitations of conventionally powered submarines. Submerged speed is listed as more than 25 knots.

Sensors and control systems

Virginia-class submarines use a large-aperture bow sonar architecture for underwater detection and tracking. Digital photonics masts replace conventional optical periscopes, allowing sensor information to be displayed electronically inside the control room.

Armament

USS Idaho carries two large-diameter Virginia Payload Tubes. Each tube can accommodate six Tomahawk cruise missiles, providing capacity for 12 missiles in this configuration. Four torpedo tubes support Mk 48 Advanced Capability heavyweight torpedoes for engagements against submarines and surface ships.

Block IV availability improvements

The principal Block IV change is an effort to increase fleet availability across the submarine's service life. The maintenance plan reduces major maintenance periods from four to three and increases the planned number of deployments from 14 to 15.

Operational history

USS Idaho began its first operational deployment within months of commissioning. The four-month mission was conducted with the U.S. Sixth Fleet in the U.S. European Command area of responsibility.

During the deployment, Idaho sailed more than 19,000 nautical miles. Its port calls included Haakonsvern, Norway, and Kings Bay, Georgia. Operations in and around northern European waters placed the submarine in a region important to monitoring maritime approaches between the Norwegian Sea, the High North, and the North Atlantic.

Idaho returned to Naval Submarine Base New London on 28 September 2026, completing its first deployment. Thirteen sailors earned submarine warfare qualifications during the mission. The submarine was assigned to Submarine Squadron 4 during this period.

Specifications (USS Idaho, Block IV)

General characteristics

• Class and type: Virginia-class Block IV nuclear-powered attack submarine
• Displacement: approximately 7,800 tons submerged
• Length: 115 m (377 ft)
• Beam: 10.4 m (34 ft)
• Propulsion: nuclear reactor plant designed to operate without refueling during the planned service life

Performance

• Submerged speed: more than 25 knots

Armament

• Missile launchers: two Virginia Payload Tubes, each capable of carrying six Tomahawk cruise missiles
• Torpedo tubes: four tubes for Mk 48 Advanced Capability heavyweight torpedoes