Rear Adm. Andrew Miller, director of the Navy’s Undersea Warfare Division, outlined the preliminary requirements for the submarine, known as SSN(X), at the Naval Submarine League’s annual conference in Arlington, Virginia, on Nov. 12.
The Navy’s latest fleet plan calls for construction to begin in the early 2040s, and the Congressional Budget Office estimates an average cost of about $9 billion per submarine.
Miller said the analysis of alternatives was nearing completion and pointed to the need for a submarine designed from scratch to preserve the U.S. undersea advantage over peer rivals by midcentury.
The Navy completed its own analysis in November 2025, and the Pentagon’s Office of Cost Assessment and Program Evaluation approved the requirements in March 2026.
The Virginia class is expected to remain the backbone of the attack submarine fleet for decades.
The Navy’s requirements for SSN(X) include higher top and tactical speeds, greater operational availability, a high degree of stealth and the ability to carry and control uncrewed and autonomous systems.
Miller said the Navy wants the new submarines to be more “friendly” to crews and shipbuilders and substantially less expensive to operate and maintain than Virginia-class boats.
Dedicated drone launch and recovery equipment is expected to require a hull about 13 meters in diameter, close to that of the Columbia class and wider than the Virginia class’s roughly 10-meter hull.
The Congressional Budget Office estimates that SSN(X) would displace more than 10,000 metric tons submerged, roughly in line with Block V and VI Virginia-class submarines.
At the same conference, the commander of the U.S. Pacific Fleet’s submarine force warned that America’s undersea advantage “is real, but is not guaranteed,” pointing to China’s seabed mapping in the western Pacific and its development of nuclear-powered attack submarines.
