A 453-foot submarine stretched by a 100-foot section spliced into its middle has worked as the US Navy’s only special warfare support boat for 21 years, carrying divers, robots and cable-handling gear

Key Points:

• The future USS Baltimore, a Block V Virginia-class submarine ordered in 2024, is being converted into a special operations and seabed warfare platform, replacing the USS Jimmy Carter, the Navy’s only special warfare support submarine for the past two decades.
• The conversion includes a special mission insert with an extended drop keel, saturation diving accommodations, controls for tethered underwater vehicles, and a specialized Non-Propulsion Electronics System, indicating a focus on prolonged underwater physical operations.
• Saturation diving allows divers to live and work at depth for extended periods, suggesting the Baltimore will conduct hands-on seabed work rather than just reconnaissance, likely involving maintenance or intervention on critical undersea infrastructure like fiber optic cables and pipelines.
• The submarine’s Virginia Payload Module, which increases missile capacity, may be partially repurposed for mission-specific equipment, reflecting a trade-off between offensive missile capability and enhanced seabed warfare functions.
• While no official delivery date or cost has been released, estimates suggest the USS Baltimore could be completed around 2036, continuing the Navy’s expansion into seabed warfare as a strategic growth area.