US Navy commissions giant 7,800-ton nuclear-powered attack submarine USS Idaho

The US Navy has officially commissioned the USS Idaho (SSN 799), a 7,800-ton nuclear-powered attack submarine, in a traditional ceremony that marked its formal entry into active service. The event took place at Naval Submarine Base New London in Groton, Connecticut, on April 25, 2026.

This vessel is the 26th Virginia-class submarine and the eighth unit delivered under the advanced Block IV configuration. Its commissioning follows a construction process led by General Dynamics Electric Boat in partnership with HII-Newport News Shipbuilding.

Measuring 377 feet in length with a 34-foot beam, the Idaho represents a significant investment in maritime infrastructure. The submarine is designed with a nuclear reactor plant that will not require refueling throughout its entire operational life.

This engineering choice is intended to reduce long-term maintenance costs and increase the amount of time the vessel can remain at sea. It can reach speeds exceeding 25 knots while submerged and is capable of operating for months without surfacing.

During the ceremony, acting Secretary Cao formally placed the ship in service. The submarine’s sponsor, Teresa Stackley, gave the traditional order to the crew to man the ship and bring her to life.

The Idaho is the fifth ship in US naval history to carry the name of the state. It joins Submarine Squadron FOUR, where it will be utilized for multi-mission requirements including surveillance and special warfare.

Block IV submarines like the Idaho focus on design changes to reduce total ownership costs. By increasing the intervals between major maintenance periods, the Navy aims to maximize the availability of these hulls for global deployments.

Construction of such vessels remains a cornerstone of large-scale naval infrastructure. The USS Idaho features enhanced stealth technology and sophisticated sonar arrays, allowing for intelligence collection and land-attack operations.

It is equipped with Virginia Payload Tubes capable of launching Tomahawk cruise missiles. These systems allow the submarine to strike targets from a significant distance, providing a versatile tool for maritime defense.

The commissioning occurs as the US Navy continues to expand its sea fleet. New infrastructure, including submarine tenders, is currently being planned to support these nuclear-powered assets as they deploy to remote regions.

The USS Idaho was previously christened in March 2024. Its transition to active duty signals the completion of years of industrial effort involving thousands of workers across the specialized shipbuilding supply chain.