USS Vermont (SSN 792)

USS VERMONT History:

USS VERMONT is a VIRGINIA-class, nuclear-powered fast-attack submarine and the first boat of the Block IV configuration. She was ordered from General Dynamics Electric Boat as part of a ten-submarine, multi-year procurement contract awarded on April 28, 2014, intended to streamline construction and reduce life-cycle costs across the class. From the outset, she was planned as a workhorse for multi-mission operations, combining traditional anti-submarine and anti-surface roles with strike, intelligence collection, and special operations support. Her name, honoring the state of Vermont, was announced by Secretary of the Navy Ray Mabus on September 18, 2014, continuing a lineage of two earlier U.S. Navy ships to bear the state's name.

Physical construction of the submarine took place at Electric Boat's Groton yard. Her keel was laid in February 2017, marking the formal start of assembly in the building ways. Over the next two years, modules were joined and systems installed. On October 20, 2018, the submarine was christened at Groton in a ceremony that reflected the state's involvement in the program; the sponsor used a bottle of Vermont sparkling apple wine to formally name the ship. After christening, she was moved from the construction hall to a floating dry dock and, on March 29, 2019, was launched into the Thames River, beginning the transition from shipyard project to operational warship.

Following launch, VERMONT spent the remainder of 2019 and the first months of 2020 in post-construction outfitting and trials. Shipyard workers and the crew verified propulsion, combat systems and hotel services in port and at sea before the Navy accepted the boat. These contractor and acceptance trials took place in the western Atlantic, using the waters off New England for submerged maneuvering and systems checks, before the submarine was ready to join the fleet formally. On April 17, 2020, Electric Boat officially delivered the submarine to the U.S. Navy. The next day, April 18, 2020, USS VERMONT was administratively commissioned in Groton, entering service as the 19th VIRGINIA-class attack submarine and the first Block IV boat. Because of the COVID-19 pandemic, the Navy held only a low-profile administrative event without the public ceremony normally associated with commissioning a capital ship, and the boat immediately began operating as part of Submarine Squadron Four out of Naval Submarine Base New London.

With her crew brought aboard and basic certifications in hand, VERMONT began to appear regularly in the Thames River and off the New England coast during 2020 as she conducted local operations from New London. Navy imagery shows the submarine underway on the river in October 2020, returning to the base after sea periods, reflecting the normal pattern for a newly commissioned submarine working through tactical and engineering training close to home. These operations took place against the broader backdrop of the U.S. Navy maintaining forward presence and readiness despite COVID-19 restrictions, with submarine crews operating in controlled "bubbles" to preserve their ability to deploy.

In December 2020, VERMONT conducted her first significant international employment when she sailed south into the U.S. 4th Fleet area of operations to visit Brazil. During this period, she visited Rio de Janeiro in support of the Brazilian Navy's PROSUB program and the launch of the conventional submarine HUMAITA (S-41). The boat's presence underscored U.S.-Brazil defense cooperation and the importance Washington attached to Brazil's indigenous submarine program. While off Brazil, VERMONT also took part in anti-submarine warfare training with the Brazilian submarine TUPI (S-30), giving both navies an opportunity to practice tracking and evasion between a modern nuclear attack submarine and a diesel-electric boat. After completing the port visit and exercises, VERMONT returned north. On December 24, 2020, she was photographed making her way up the Thames River past New London as she returned to Naval Submarine Base New London, and movement records show her mooring that day at Pier 17S on the base after the South Atlantic voyage.

Almost immediately, VERMONT moved into another phase of specialized testing. From January 17-20, 2021, she conducted acoustic trials off the coast of Port Everglades, Florida, operating in carefully controlled ranges to measure and characterize her noise signature and confirm the effectiveness of machinery isolation and hull treatments. She then conducted a second set of acoustic trials in the same area from January 22-25, 2021, refining the data needed to ensure the submarine met stringent stealth requirements. After completing this work, she returned north. On February 3, 2021, Navy photographs show VERMONT again transiting up the Thames River through a winter snow squall to return to Submarine Base New London after routine operations, a likely end point of the Florida acoustic-trial period.

Through the rest of 2021, VERMONT continued to operate from New London under Submarine Squadron Four, with open-source reporting indicating a pattern of local and regional training in the western Atlantic and off the U.S. east coast. These operations included further at-sea periods to exercise sonar, weapons handling and navigation systems, along with continued crew training to build experience on the new Block IV platform. For most of this time, she remained without a traditional public commissioning ceremony because of the earlier pandemic restrictions, even though she was fully active in the fleet.

That changed late in the summer of 2021. On August 28, 2021, the Navy held a full commissioning commemoration for USS VERMONT at Naval Submarine Base New London. At this ceremony, which took place on the pier with the boat alongside, the crew "manned the ship" in the traditional fashion while the Secretary of the Navy Carlos Del Toro and other dignitaries formally marked her entry into service. The event emphasized both VERMONT's status as the first Block IV VIRGINIA-class submarine and the connection between the boat and its namesake state. Media reports noted the continued impact of COVID-19 precautions on attendance, but the ceremony gave the submarine the public milestone that had been missing since April 2020 and marked the completion of her transition from new-construction unit to fully integrated attack submarine in the operational force.

During 2022, USS VERMONT remained based at New London and continued operating with Submarine Squadron Four. Publicly available information for this period is relatively sparse, reflecting the routine confidentiality surrounding attack submarine schedules. Imagery and occasional mentions in Navy communications, however, indicate that the submarine carried out repeated underways for training and readiness in the Atlantic, consistent with a newly commissioned boat that had completed initial tests and was now focused on building crew proficiency and integrating into fleet exercises. There is no open evidence of a long overseas deployment during 2022; rather, the pattern appears to have been one of recurring short sea periods from her Connecticut homeport.

By 2023, the Navy had decided to shift VERMONT to the Pacific to strengthen the attack-submarine presence in the Indo-Pacific region. Early that year, she remained associated with New London, but by mid-summer she had completed preparations for a homeport change. On July 27, 2023, the submarine arrived at Joint Base Pearl Harbor-Hickam in Hawaii, where she was greeted by traditional Hawaiian dancers and representatives of Submarine Squadron One as she moored in her new homeport. From that point forward, VERMONT was administratively assigned to Submarine Squadron One and integrated into the fast-attack submarine force that supports U.S. Pacific Fleet operations, part of the wider U.S. effort to concentrate advanced undersea capabilities in the Indo-Pacific in response to growing Chinese naval power and continuing regional tensions.

Following the arrival in Pearl Harbor, VERMONT spent late 2023 and the first half of 2024 operating from Hawaii. Navy releases describe this period in general terms as routine training and local operations in the Hawaiian operating areas, as the crew adapted to Pacific Fleet procedures and worked through workups for an initial deployment from the new homeport. During this time, ties with the state of Vermont continued to develop. On April 18, 2024 - the fourth anniversary of her administrative commissioning - the Vermont legislature formally designated that date as "USS VERMONT (SSN 792) Day" in the state, noting the crew's use of the nickname "Big Sugar" and the motto "Freedom and Unity" as expressions of their connection to Vermont traditions. That resolution, and associated events involving the ship's sponsor and support group, reinforced the symbolic bond between the submarine and its namesake state even as the boat now operated from the central Pacific.

In August 2024, USS VERMONT departed Pearl Harbor for her first Western Pacific deployment. Under the command of Cmdr. Michael Lilleberg, she deployed to the U.S. 7th Fleet area of responsibility on a seven-month cruise that highlighted her role in forward deterrence and allied engagement. During this deployment, the submarine conducted a variety of operations that the Navy has described broadly as supporting regional maritime security, working with allies and partners, and preserving a free and open Indo-Pacific. Specific details of her submerged tasking remain classified, but publicly reported port visits provide a clear outline of some of her movements.

On September 23, 2024, VERMONT arrived at Busan Naval Base in South Korea, becoming the first U.S. submarine whose Busan visit had been publicly disclosed in several months. Navy photographs and press accounts describe the port call as an opportunity for replenishment and engagement with Republic of Korea Navy officials. During the visit, Rear Adm. Chris Cavanaugh's counterpart Rear Adm. Kang and other South Korean leaders visited the submarine. The port call drew sharp rhetorical criticism from North Korea, underlining the symbolic weight of U.S. nuclear-powered submarine visits to the Korean Peninsula at a time of ongoing missile tests and heightened regional tension. After several days in Busan, the submarine returned to sea to resume her deployment.

By September 30, 2024, VERMONT had been photographed in Sasebo, Japan, making a port visit to the U.S. Naval facilities there. Images shared by official channels show the submarine alongside at the Akasaki fuel and logistics facilities, underscoring her role in the U.S. undersea presence that supports American and Japanese maritime security commitments. After leaving Sasebo she again operated at sea in the western Pacific, conducting the unpublicized portion of her tasking in support of 7th Fleet operational plans.

In December 2024, VERMONT made an extended visit to Yokosuka, Japan, the headquarters of U.S. 7th Fleet. On December 9, 2024, she moored at Commander, Fleet Activities Yokosuka, where Navy imagery records her beginning mooring operations as she arrived in port. She remained alongside at least through December 12, when Rear Adm. Chris Cavanaugh, commander of Submarine Group 7, joined Royal Australian Navy officers on the pier to recognize the qualification of an Australian submariner in U.S. "dolphins" - the submarine warfare insignia - earned while embarked in VERMONT during the deployment. That event highlighted the submarine's contribution not only to U.S. operations but also to the AUKUS framework and broader allied undersea integration, as Australian personnel gained hands-on experience aboard a VIRGINIA-class nuclear submarine.

After departing Japan, VERMONT continued her deployment with further operations and at least one major port visit to U.S. territory. On January 20, 2025, she was documented transiting Apra Harbor at Naval Base Guam, indicating an in-port period there while still on deployment in the 7th Fleet area. Guam serves as a key logistics and maintenance hub for U.S. submarines in the western Pacific, and the visit allowed the crew to conduct resupply and maintenance while remaining relatively close to operational areas. The deployment as a whole, according to official Navy accounts, balanced such port calls with extensive time at sea, where the submarine contributed to undersea surveillance, forward deterrence, and support for joint and combined exercises.

USS VERMONT returned to Pearl Harbor on March 16, 2025, completing her maiden Western Pacific deployment after roughly seven months underway. Families greeted the boat on the pier at Joint Base Pearl Harbor-Hickam, and the Navy highlighted not only the operational accomplishments of the deployment but also the fact that more than one hundred sailors had qualified in submarines during the cruise, strengthening the crew's professional base.

In the months following her return, VERMONT entered a post-deployment cycle of leave, maintenance and local operations from Pearl Harbor. Publicly released information indicates that she continued to serve under Submarine Squadron One, with additional emphasis on integration with AUKUS partners. That role culminated late in 2025, when USS VERMONT undertook a highly visible maintenance period in Australia. On October 29, 2025, she arrived at HMAS Stirling, the Royal Australian Navy's principal submarine base in Western Australia, to begin a scheduled Submarine Maintenance Period. Australian and U.S. authorities emphasized that this would be a landmark event: it was the first time a U.S. nuclear-powered attack submarine had undergone a full maintenance package in Australia without the support of a U.S. tender ship. The visit formed part of the broader effort to establish the Submarine Rotational Force - West and to build Australian sovereign sustainment capability for conventionally armed nuclear-powered submarines under AUKUS.

During roughly four weeks alongside at HMAS Stirling, VERMONT became a live training and work platform for a combined team. Royal Australian Navy personnel, technicians from Australia's submarine company ASC, and U.S. Navy and Pearl Harbor Naval Shipyard specialists worked together on more than 160 maintenance tasks. Australian sources highlight the use of a specially developed mobile pure-water plant and bespoke access platforms around the submarine's sail, as well as extensive exercises in radiological stewardship procedures - all designed to demonstrate that complex maintenance could be conducted safely on a visiting U.S. SSN. The boat's crew worked closely with the mixed maintenance team, while a contingent of Royal Australian Navy submariners who had trained in the United States served as part of VERMONT's ship's company, gaining operational and maintenance experience at sea and alongside.

On November 28, 2025 the Australian Submarine Agency reported that USS VERMONT had departed HMAS Stirling after completing the maintenance period, marking the successful conclusion of the Submarine Maintenance Period and another incremental step toward the planned rotational presence of U.S. and U.K. nuclear-powered submarines in Western Australia. For VERMONT, the visit underscored her role not only as an operational attack submarine but also as a tangible instrument of alliance policy, used to transfer skills and build infrastructure for a future in which American and Australian crews will routinely share the sustainment and operation of nuclear-powered platforms.

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