Current Navy SEAL Undersea Fleet: SDVs, SWCS, and DCS
Are underwater drones used by Navy SEALs? Yes — and the program is growing fast. Here is a quick summary:
- Currently in testing: The U.S. Navy is actively testing uncrewed underwater vehicles (UUVs) alongside SEAL mini-submarines.
- Not yet fully operational: As of June 2026, UUV-SDV teaming is still years away from the reliability level operators require.
- Main purpose: UUVs act as robotic scouts, swimming ahead of SEAL teams into dangerous areas to detect mines, obstacles, and enemy defenses.
- Key vehicles involved: The Mk 11 Shallow Water Combat Submersible (SWCS) and the Dry Combat Submersible (DCS) are the two crewed platforms being paired with UUVs.
- Biggest hurdle: Radio waves don't travel through saltwater, making real-time communication between drones and manned submersibles extremely difficult.
The U.S. Navy envisions a future in which robotic underwater vehicles work alongside SEAL mini-submarines — much like unmanned wingman drones do in modern air combat. The idea is simple: send the drone through the dangerous part first, so the SEALs know what they're swimming into.
But the underwater world is unforgiving. As one Navy captain put it, current systems are essentially "deaf, dumb, and blind" when it comes to communicating with each other beneath the surface. Solving that problem is what separates today's testing from tomorrow's battlefield capability.
I'm Larry Fowler, publisher of the USMilitary.com Network since 2007 and a long-time tracker of special operations technology trends — including the question of whether underwater drones are used by Navy SEALs and where that capability is headed. In the sections below, we'll break down exactly how these systems work, what's holding them back, and what the future looks like for SEAL underwater operations.
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Before we can look at how uncrewed underwater vehicles (UUVs) are transforming special operations, we have to understand the manned platforms that United States Navy SEALs use to navigate the ocean depths. For decades, the primary tool for clandestine maritime insertion has been the SEAL Delivery Vehicle (SDV).
Historically, these submersibles have been managed by specialized SDV Teams, which represent a highly strategic but physically punishing niche within Naval Special Warfare. Riding in a traditional SDV is not a luxury cruise. Historically, these have been "wet" submersibles, meaning the cabin is completely flooded with seawater. SEALs must wear full diving gear, breathe from the vehicle's compressed air supply (or their own rebreathers), and endure hours of freezing temperatures. It is a grueling experience that some operators have described as being locked in a cold, dark coffin.
To understand What Do Navy Seals Do? in the modern era, we must look at the transition to newer, more capable platforms:
- Mk 11 Shallow Water Combat Submersible (SWCS): This is the modern successor to the legacy Mark 8 SDV. It remains a "wet" vehicle, but it features significantly updated navigation, communications, and cargo capabilities. Measuring just under 22.5 feet long, it is operated by a crew of two and can carry up to six passengers (or combat divers).
- Dry Combat Submersible (DCS): Reaching initial operational capability under a $166 million contract, the DCS represents a massive leap forward in operator comfort and endurance. Unlike the wet Mk 11, the DCS is a fully dry, pressurized mini-submarine. It measures 39.4 feet long, displaces 28 tons fully loaded, and accommodates a crew of two alongside eight passengers. Because operators stay dry and warm during transit, they arrive at their destination without the crushing fatigue caused by hours in freezing water.
The SEAL Delivery Vehicle (SDV) History shows a steady march toward greater range and stealth. However, even with these advanced submersibles, human operators still face extreme risks when navigating contested waters. That is where robotic systems enter the picture.
Submersible Specifications Comparison
| Feature | Mk 11 SWCS (Wet Sub) | Dry Combat Submersible (DCS) |
|---|---|---|
| Type | Free-flooding (Wet) | Pressurized Cabin (Dry) |
| Length | ~22.5 feet | 39.4 feet |
| Weight / Displacement | Lightweight / Compact | 28 tons (fully loaded) |
| Crew Capacity | 2 Crew + 6 Passengers | 2 Crew + 8 Passengers |
| Operating Depth | Shallow water limits | Up to 330 feet |
| Endurance / Range | Limited by diver thermal limits | Over 24 hours / 69 miles |
| Primary Launch Method | Submarine Dry Deck Shelter (DDS) | Surface vessels or specialized carriers |
Are Underwater Drones Be Used By Navy SEALs?
The short answer is yes, but not in the way you might expect. They are not replacing human divers; instead, they are acting as "robotic wingmen."
The Navy is currently exploring crewed-uncrewed teaming (MUM-T) concepts that pair the Mk 11 SWCS and the DCS with autonomous, torpedo-shaped uncrewed underwater vehicles (UUVs). Under Navy Undersea Warfare Advancements, the goal is to use these drones as scouts, shields, and decoys.
Testing of these capabilities is primarily led by the Naval Surface Warfare Center, Panama City Division in Florida. The vision is to launch a UUV directly from, or alongside, a SEAL mini-submarine. The drone swims ahead into high-risk areas—like heavily defended enemy harbors or narrow choke points—to map out the area. If there are mines, underwater obstacles, or active sonar arrays, the drone detects them first, keeping the human operators out of harm's way.
Several existing drone programs are shaping this effort:
- Yellow Moray: This program has successfully demonstrated the launch and recovery of a REMUS 600 UUV through a submarine's standard torpedo tubes. This is a critical milestone because it proves that tactical-sized drones can be deployed covertly from a submerged platform.
- Razorback: The Navy has been testing the Razorback UUV for environmental sensing and submarine-launched reconnaissance. While the program has faced setbacks—including the cancellation of a specific torpedo-tube-launched variant—testing with Dry Deck Shelters on allied vessels, such as French Navy submarines, has continued to yield valuable operational data.
- Snakehead: This large displacement UUV was designed for long-range missions, though it was canceled due to integration challenges with Navy submarines.
These programs highlight the rapid evolution of the Future of Drone Warfare. The Special Operations community is taking lessons learned from these larger fleet programs and scaling them down to fit the tight physical limits of SEAL tactical craft.
Technical and Operational Challenges of UUV-SDV Teaming
While the concept of pairing Navy SEALs with underwater drones is incredibly promising, actually making it work in the real world is an engineering nightmare. The undersea domain is one of the most hostile environments on Earth for electronic systems.
According to research from the Naval Undersea Warfare Center Research, there are several major hurdles that must be solved before UUV-SDV teaming becomes a reliable battlefield reality:
1. The Communication Bottleneck
In the air, drones rely on radio frequencies, GPS, and satellite links to exchange massive amounts of data in real time. None of those work underwater. Saltwater completely blocks electromagnetic waves.
Currently, underwater systems are largely "deaf, dumb, and blind" to one another. To communicate, they must rely on:
- Acoustic Modems: These send data via sound waves. While acoustic signals can travel long distances, they have incredibly low bandwidth (think dial-up internet speeds from the 1980s) and can easily be intercepted or jammed by the enemy.
- Optical (Blue-Green Laser) Communications: These can transmit high-bandwidth data over short distances. However, they require a direct line of sight and can easily be disrupted by muddy or turbulent coastal waters.
2. Launch and Recovery Constraints
Launching a drone is relatively simple, but recovering it while submerged is incredibly difficult. Historically, retrieving a UUV required sending out human combat divers to manually grab the drone and secure it. This defeats the purpose of using an unmanned system to reduce human risk. The Navy is working on automated docking stations and robotic arms, but these systems are still highly temperamental.
3. Volume and Space Constraints
The Mk 11 SWCS is incredibly compact. There is barely enough room for the operators, their gear, and their life-support systems. Finding space to store, transport, and launch a torpedo-sized drone is a massive physical challenge. Planners have even experimented with strapping drones to the outside of the submersibles, but this adds hydrodynamic drag and increases the vehicle's acoustic signature.
Future Missions and Stealth Upgrades for Combat Divers
When these integration challenges are finally overcome, teamed UUVs will unlock entirely new mission sets for Navy SEAL training graduates.
Instead of risking human lives to perform dangerous harbor penetrations or hydrographic reconnaissance of hostile beaches, a UUV can be sent ahead to map the seafloor. If the drone is detected and destroyed, the Navy loses a piece of hardware—not a highly trained special operator.
At the same time, USSOCOM Technology Developments are focusing heavily on making the human combat divers themselves far more difficult to detect. As adversaries like China and Russia deploy advanced undersea sensor networks, stealth is more critical than ever.
Several key areas of stealth and capability upgrades are currently being pursued:
- Advanced Signature Management: USSOCOM is actively seeking technologies to reduce the acoustic, thermal, and electromagnetic signatures of both the submersibles and individual divers. Even a diver's heating suit can generate a thermal signature that advanced passive sensors can detect.
- Closed-Circuit Rebreathers: Unlike traditional SCUBA gear that releases bubbles, modern military rebreathers recycle the diver's exhaled breath. They produce zero bubbles, run completely silent, and leave no surface signature.
- Jetboots Propulsion: To increase a diver's speed and range without causing physical exhaustion, the military uses custom-built, hands-free thrusters like Patriot3 Marine's Jetboots. These battery-powered thrusters can propel a swimmer at an additional four knots for up to 12 miles on a single charge, allowing them to slip past coastal defenses effortlessly.
Frequently Asked Questions About Navy SEAL Undersea Tech
Are Underwater Drones Be Used By Navy SEALs for Mine Detection?
Yes. Mine countermeasures (MCM) are one of the primary missions envisioned for UUV-SDV teaming. Drones like the REMUS 600 can be equipped with side-scan sonar to map out underwater minefields, allowing SEALs to navigate safely around them or mark them for demolition.
Are Underwater Drones Be Used By Navy SEALs to Scout Hostile Harbors?
This is a major area of development. Sending a manned mini-submarine into a heavily fortified enemy harbor is incredibly risky. Sending a small, low-profile UUV to scout the harbor entrance, locate enemy hulls, and identify defensive sensors is a much safer way to conduct reconnaissance.
What is the difference between a wet and dry submersible?
In a wet submersible (like the Mk 11 SWCS), the cabin is completely flooded, and the divers must wear full diving gear and expose themselves to cold water temperatures. In a dry submersible (like the DCS), the cabin is sealed and pressurized, allowing the operators to travel in a dry, climate-controlled environment without wearing diving gear until they exit the vehicle.
Conclusion
The question is no longer whether underwater drones are used by Navy SEALs, but rather how quickly these systems can be fully integrated into the fleet. While the technology is still in the testing and refinement phase as of June 2026, the strategic benefits of crewed-uncrewed teaming are too massive to ignore. By acting as scouts and shields, UUVs will allow Navy SEALs to operate deeper inside contested territory with lower risks than ever before.
If you want to dive deeper into special operations, check out our Navy SEALs Complete Guide or explore our resources on Navy SEALs careers. Here at USMilitary.com, we are committed to keeping our service members, veterans, and their families informed on the latest advancements in defense technology and military benefits.
