USS Massachusetts (SSN 798) becomes the 25th Virginia-class submarine delivered to the U.S. Navy.

The U.S. Navy accepted the future USS Massachusetts (SSN 798) on November 21, 2025, after the submarine completed its initial sea trials in the Atlantic in October.

On November 21, 2025, the U.S. Navy announced the delivery of the future USS Massachusetts (SSN 798) from HII’s Newport News Shipbuilding facility in Virginia, marking the official transfer of the Virginia-class submarine to the fleet as final testing continues before a commissioning planned for spring 2026 in Boston. This delivery took place after the submarine completed initial sea trials in October 2025, including its first submergence and high-speed maneuvers. The acceptance of the USS Massachusetts represents the latest production milestone in the Virginia-class attack submarine program, which remains central to the U.S. current and future naval force planning.
Follow Army Recognition on Google News at this link

The USS Massachusetts (SSN 798) is the 25th Virginia-class submarine to be produced under the arrangement between HII’s Newport News Shipbuilding and General Dynamics Electric Boat, and it is the 12th Virginia-class submarine delivered by Newport News. (Picture source: HII)

The USS Massachusetts (SSN 798) is the 7th Virginia-class submarine configured in the Block IV standard, which is designed to reduce major maintenance periods and increase the number of operational deployments over its service life. Ordered on April 28, 2014, as part of a 17.6 billion dollar contract for ten Block IV submarines allocated between the two shipyards, the Massachusetts' keel was laid on December 11, 2020, during a virtual ceremony conducted under COVID-19 restrictions, and its pressure hull reached completion in August 2022 when the major hull sections were joined. The submarine was then christened on May 6, 2023, by sponsor Sheryl Sandberg and launched into the James River by floating dry dock on February 23, 2024. Following this launch ceremony, tugboats moved the submarine to a dedicated pier for outfitting, testing, and crew certification activities. More than 10,000 shipbuilders from Newport News and Electric Boat contributed to the construction effort, supported by thousands of suppliers nationwide. Furthermore, more than 20 suppliers located in the state of Massachusetts provided components and services for the submarine.

Following this, the USS Massachusetts completed its initial sea trials on October 7, 2025, during several days of testing in the Atlantic Ocean conducted jointly by the U.S. Navy and Newport News evaluation teams. These trials included the submarine’s first submergence, its first sustained high-speed runs both at depth and on the surface, and the testing of major propulsion, combat, navigation, and auxiliary systems. The trials also involved the verification of the submarine’s response during maneuvering and the performance of its integrated components under operational conditions. The successful completion of these events permitted HII's Newport News to confirm the readiness of the Massachusetts for its delivery to the U.S. Navy. Post-trial inspections and certification activities then continued pier-side to resolve remaining procedural checks before the final acceptance. U.S. Navy representatives also announced that additional trials and inspections would continue through early 2026 to prepare the submarine and crew for the official commissioning ceremony, which is planned for spring 2026 in Boston Harbor, according to the commissioning committee. The U.S. Navy also stated that a commissioning in Boston is consistent with earlier announcements made in November 2023 regarding the submarine’s planned ceremonial location.

Technically, the USS Massachusetts follows the Virginia-class Block IV standard with a length of approximately 115 meters, a beam of about 10.4 meters, and a draft of 9.8 meters. Its submerged displacement is roughly 7,800 tonnes for Block I to Block IV units, and its propulsion system consists of a single S9G pressurized water reactor (PWR), estimated to generate 210 megawatts (MWt), coupled to steam turbines to deliver a combined 40,000 shaft horsepower (29.8 MW) to a single pump jet propulsor. The reactor is designed for a core life of approximately 33 years, allowing the submarine to operate with endurance limited mainly by food supply and scheduled maintenance cycles rather than fuel. The submarine’s certified test depth is greater than 244 meters, and unofficial references place potential operational depth significantly deeper, although these figures are not confirmed. The USS Massachusetts will operate with a standard crew of about 135 personnel, including 15 officers and 120 enlisted sailors. Its maximum speed is stated as greater than 25 knots (46 km/h), which aligns with established performance values across earlier units of the class. The submarine’s armament consists of four 533 millimeter torpedo tubes for Mk 48 torpedoes and launch capability for UGM-84 Harpoon missiles. Finally, two large Virginia payload tubes provide the capacity to deploy twelve Tomahawk land-attack cruise missiles through vertically launched canisters.

Succeeding to the Seawolf- and Ohio-classes, the Virginia-class also incorporates a series of technological advancements that also apply to the USS Massachusetts, including photonics masts replacing the traditional optical periscopes. These masts incorporate high-resolution color cameras, infrared sensors, low-light imaging, an infrared laser rangefinder, and integrated electronic support measures, all connected via fiber-optic lines to the control center. This allowed the submarine’s command center to be relocated from beneath the sail to a position within the pressure hull that is independent of periscope geometry. The class also employs universal modular masts supporting communications, radar, and electronic warfare systems, standardizing structural and mechanical interfaces. Sonar systems use an open architecture format, enabling regular hardware insertions and software builds to maintain a high acoustic performance. The hull features wide aperture flank arrays, high frequency chin and sail arrays, and towed thin and fat line arrays for long range detection. The pump jet propulsor reduces cavitation and acoustic signature compared to traditional propellers, improving stealth characteristics. Additional features include an integral lock-out trunk for special operations forces and a modernized command and control suite integrating multiple combat system elements.

The USS Massachusetts also fits within the broader production schedule of the Virginia-class, which entered service in 2004 with the commissioning of the USS Virginia (SSN 774) and has since grown into the most numerous active submarine class in the world following the July 2025 decommissioning of the USS Helena. The class was originally conceived to replace Los Angeles-class attack submarines and four Ohio-class cruise missile conversions as they retire from service. Construction relies on modular techniques that reduce labor hours by assembling major equipment segments outside the hull before integration. In terms of upgrades/blocks, Block II reduced the number of hull modules from ten to four, saving around 300 million dollars per boat and reducing construction time. Block III then introduced the large aperture bow sonar array and two large payload tubes in place of twelve individual Tomahawk launchers. Block IV, which now includes the Massachusetts, further reduces major maintenance periods from four to three across its planned service life. And the future Block V will introduce the Virginia Payload Module, adding a 21-meter mid-body section containing four additional payload tubes capable of deploying twenty-eight additional Tomahawk missiles.

The Virginia-class program continues to expand with the ongoing construction of Block IV and Block V submarines and preparations for Block VI, which is planned to incorporate enhancements for seabed warfare and advanced undersea communications. Nine Virginia-class submarines are currently under construction, and four additional units have been authorized, contributing to a total planned class size of sixty-six boats. The U.S. Navy has stated that the Virginia-class will remain in service at least into the 2060s, with later units projected to operate beyond the 2070s. The program relies on a dual shipyard industrial base to maintain production resilience, with Newport News and Electric Boat alternating major component assembly and final construction. The Navy has emphasized the need to increase production from 1.2 to approximately 2.2 submarines per year to meet both U.S. and AUKUS requirements. Under the AUKUS agreement announced in March 2023, Australia is expected to purchase three Virginia-class submarines in the early 2030s with options for two more. Elements of Virginia-class technology, including propulsion plant components and combat system elements, will also inform the trilaterally developed SSN-AUKUS submarine class.

Additionally, the USS Massachusetts also continues the historical lineage of U.S. Navy ships bearing the name of the Commonwealth of Massachusetts, making it the fifth Navy vessel to carry the name and the eighth overall vessel connected to the state. Its predecessors include a transport steamer used in the Mexican-American War and the South Dakota class battleship USS Massachusetts (BB-59), commissioned in 1942 and awarded eleven battle stars for World War II service before decommissioning in 1947. The BB-59 now serves as a museum ship at Battleship Cove in Fall River, Massachusetts, establishing a public historical link carried forward by the SSN 798. The Navy has confirmed that Massachusetts will be stationed initially without a designated homeport until after commissioning. During the delivery announcement, Navy and industry officials highlighted the continuation of construction milestones across the fleet, including the delivery of USS Pierre (LCS 38), the destroyer Harvey C. Barnum Jr. (DDG 124), and the christening of USS Utah (SSN 801).

Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.