GAO Report: US Navy Submarines Idle Amid Shipyard Backlog

Shipyard Capacity Crunch Leaves Submarines Stranded

A new audit from the US Government Accountability Office (GAO) has turned a critical eye on the US Navy’s submarine fleet, concluding that dozens of attack submarines are sitting unused for months or years because shipyards simply cannot absorb the workload. According to the Maritime Executive’s coverage of the report, the GAO found that idle time has become a persistent feature of submarine life cycles over the past decade, driven by a chronic inability to secure dock space for both scheduled maintenance and end-of-life decommissioning.

The numbers are striking. Over the last ten years, maintenance delays and idle periods on active submarines have cost the Navy more than 15,000 operational days, translating into an estimated $3.4 billion spent sustaining crews and vessels that delivered no operational value. A further $3.1 billion has been lost to decommissioning delays, where boats cannot even begin the process of being taken out of service because yards lack the capacity to handle reactor defueling and related work.

A Fleet Stretched Thin

The Navy’s 44 attack submarines — 20 Los Angeles-class and 24 Virginia-class boats — depend on just four public shipyards (Portsmouth, Norfolk, Puget Sound, and Pearl Harbor) plus two private yards operated by General Dynamics and Huntington Ingalls Industries. These facilities are tasked simultaneously with new construction, depot-level maintenance that can run 24 to 36 months, and decommissioning work. The GAO notes this backlog has existed since 2008, and the public yards are currently completing only about 11 percent of depot maintenance on schedule.

The decommissioning side of the problem is arguably worse. Over the past five years, seven submarines awaiting decommissioning accumulated 2,216 idle days between them, at a cost exceeding $480 million — and the GAO warns that, absent intervention, 15 more boats will enter this same inactive status over the next four years, racking up over 14,000 idle days and $3.1 billion in further costs.

The case of USS Pasadena (SSN-752) illustrates the scale of the issue. The Los Angeles-class boat went idle in January of last year and is not expected to reach Norfolk Naval Shipyard for decommissioning until November 2028 — a wait of 1,414 days. The submarine remains fully crewed throughout, with costs for that idle stretch projected at $300 million.

The GAO also flagged knock-on effects for new construction: as of mid-2025, Virginia-class submarine production had slowed to one boat per year against a target of two, and the most recent deliveries arrived more than three years behind schedule.

Why This Matters Beyond Naval Circles

While this report concerns a military fleet, it offers a useful cautionary tale for commercial ship owners and managers about the risks of yard capacity bottlenecks. When demand for dry-docking, repair, and decommissioning work outstrips available slots — whether at naval or commercial yards — the costs are not confined to the yard bill. Crewing, insurance, class compliance, and opportunity costs from an idle asset accumulate daily, often invisibly, until a report like this one puts a dollar figure on it.

For commercial operators, the lesson is in forward planning. Vessels that arrive at a yard with an unclear condition picture, undocumented defects, or maintenance deferred beyond what surveys recommend are far more likely to extend their time in dock, competing for the same limited slipway and crane capacity as everyone else. Regular condition surveys and engine room inspections that flag issues early allow owners to schedule yard periods with realistic scope and duration, rather than discovering problems only once the vessel is already occupying a berth. In a tightening global repair and newbuild market — where yard capacity is a recurring theme across both naval and commercial shipbuilding — the operators who arrive at the yard gate with accurate, survey-backed condition data will be the ones who get in and out on schedule.

The GAO’s conclusion is blunt: the Navy has not fully explored alternative decommissioning approaches or built an inactivation plan that could shrink idle time and recover billions in wasted spending. Whether that prompts policy change remains to be seen, but the underlying dynamic — too many assets chasing too little yard capacity — is one the wider maritime industry should watch closely.