U.S. Navy Tests SEAL Mini-Subs Teamed With Drones

The U.S. Navy is working to pair its SEAL mini-submarines with uncrewed underwater vehicles, sending robotic scouts ahead of operators into the most defended stretches of any covert mission.

Navy Captain Mike Linn confirmed the program at SOF Week 2026 in Tampa, where he heads the Naval Special Warfare program office. The goal is straightforward. Push a drone through the choke point first, so the SEAL boat behind it knows what it’s swimming into.

The Mini-Subs Doing the Work

Two crewed submersibles anchor the program. The first is the Mk 11 Shallow Water Combat Submersible, a 22.5-foot “wet” boat that carries a crew of two and six passengers exposed to the water. It deploys from host submarines through a Dry Deck Shelter mounted on the aft hull.

The second is the Dry Combat Submersible, designated S351 Nemesis and built by Lockheed Martin. It measures 39.4 feet, displaces 28 tons fully loaded, and carries a crew of two plus eight fully equipped SEALs inside three pressurized compartments. Operators stay dry and rested for the entire run.

The DCS has a maximum operating depth of 330 feet and a range of about 69 miles at 5.75 mph. Lockheed Martin claims more than 24 hours of endurance, triple what the older SEAL Delivery Vehicle offered.

The program reached initial operational capability in May 2023, two boats delivered, under a $166 million contract awarded in June 2016. The DCS is too large for existing Dry Deck Shelters, so it has to be launched and recovered from a surface mothership.

Drones as Scouts and Shields

Linn framed the uncrewed piece as a risk-reducer. A torpedo-shaped UUV pushed into a defended harbor can sniff for mines, map obstacles, and absorb whatever first contact comes back, before a single operator is committed. The same drone can extend the SEAL team’s reach by carrying sensors on an independent leg of the mission after release.

This is part of a wider Navy effort to make UUVs deployable from both surface vessels and submarines. The Naval Surface Warfare Center Panama City Division is leading the testing for the SEAL teaming concept. Panama City is also where most of the Navy’s mine warfare and special operations underwater work has lived for decades, so the location is not a surprise.

The Razorback Lesson: Progress and Setbacks

The state of underwater drone integration is uneven, and Linn was honest about that. The Razorback UUV, one of the closest things the Navy has to a workable scout for this role, scored a real milestone in March 2026 when a French Suffren-class nuclear attack submarine launched and recovered one through its Dry Deck Shelter. That was the first deployment of a U.S. Razorback from an allied SSN.

As The War Zone reported, the setback came in the same fiscal year. The Navy canceled the Razorback variant designed to launch and recover through a standard submarine torpedo tube, a capability that would have removed the need for a Dry Deck Shelter at all. An earlier project called Snakehead was scrapped in 2023 for the same family of reasons. It was too large to work cleanly with a DDS.

The Yellow Moray effort is the bright spot. A REMUS 600 drone was launched and recovered through a torpedo tube on USS Delaware, a Virginia-class attack submarine forward-deployed in the European theater. Yellow Moray proves the concept works in operational conditions. Razorback’s torpedo-tube cancellation proves scaling it to a purpose-built combat UUV is still hard.

Why Underwater Coordination Is So Hard

Linn described the current state of crewed-uncrewed underwater communication as “deaf, dumb, and blind.” That quote is doing a lot of work. Radio waves do not travel through saltwater, so the Navy is leaning on acoustic links and light-based modalities. Both can be detected if used carelessly, which defeats the entire point of sending a SEAL boat in quietly.

There is also a physical constraint. The Mk 11 SWCS has very limited internal volume, which restricts how many UUVs it can carry and how big those UUVs can be.

The DCS has more room, but launching and recovering a drone from inside a sealed pressurized compartment is its own engineering problem. Synchronizing two vehicles that cannot talk to each other freely, in water that swallows signals, is not something you solve with a software update.

Linn was direct on the timeline. “I think we’re still years away from having something at the reliability level that they want,” he said. Translation: the operators will not stake a mission on this until the failure rate drops to something they can live with. That is a high bar in special operations work.

DroneXL’s Take

What Linn described at SOF Week is honest in a way the defense industry rarely allows itself to be. The Navy is not announcing a fielded capability. It is telling its own community that the underwater teaming problem is harder than the surface and air versions, and that operators are not going to get a working version this year, or next.

The aerial drone world has spoiled us. We have grown used to Group 1 and Group 2 quadcopters that simply work, talk to a controller in real time, and stream HD video over a clean datalink. None of that translates underwater. Saltwater eats signals, GPS does not exist below the surface, and the acoustic environment is a mess of biological noise and bouncing returns.

What I find genuinely significant is how the Navy is dealing with that reality. Instead of forcing a single UUV to do everything, it is keeping the SWCS, the DCS, the Razorback, and the Yellow Moray work running in parallel. Some of those programs will die quietly, as Snakehead and the torpedo-tube Razorback already have. The ones that survive will be the ones that make SEAL missions safer, not the ones with the slickest renderings on a conference stage.

The drone scouts will get there eventually. The operators going in behind them will be the ones who decide when “eventually” arrives.

Photo credit: U.S. Navy