Sailors assigned to Naval Special Warfare Group 2 conduct military dive operations off the East Coast of the US. Credit: U.S. Navy photo by Senior Chief Mass Communication Specialist Jayme Pastoric/Released.

America’s secretive Navy SEAL commando unit, one of the most capable Special Forces units in the world, has revealed it is doing a special minisub test off the coast of Hawaii.

US Special Operations Command announced it will attempt to launch and recover a new Mark 11 minisub from a Virginia-class submarine — as the elite force retools some of its undersea assets, William Cole of The Honolulu Star-Advertiser reported.

Two of the 22-foot SEAL Delivery Vehicle Mark 11s already were delivered to Hawaii for fleet familiarization and two more were undergoing government acceptance, said Capt. Kate Dolloff, Special Operations Command’s maritime program executive officer. At least ten are to be built, she added.

SEAL Delivery Vehicle Team 1 at Pearl Harbor has operated older Mark 8 delivery vehicles that are challenged “with technology obsolescence ” and are slated to be replaced one-for-one by the newer, slightly larger and 4,000-pounds-heavier Mark 11s.

Each of the “next generation “10, 000-pound, free-flooding vehicles — which still require the use of wetsuits and scuba gear — carry two crew and four passengers and have better navigation and greater payload abilities, the report said.

The submersibles are launched from watertight Dry Deck Shelters that are fitted to and connected with larger host submarines.

Mark 11 builder Teledyne Brown Engineering, awarded a US$178 million sole-source contract in October, said the minisub, also known as the Shallow Water Combat Submersible, is “specifically designed to insert and extract Special Operations Forces in high-threat areas.”

“The big takeaway here is we’re fielding a much more capable platform to the fleet, and we’ve got it out there with the operators working on it now, ” Dolloff said at the virtual Special Operations Forces Industry Conference, the report said.

Naval Special Warfare operators onboard SEAL Delivery Vehicle (SDV) Mark 11 conduct routine navigation training. Credit: U.S. Navy photo by Chief Mass Communications Specialist Christopher Perez/Released.

Special Operations Command — like the rest of the U.S. military — is grappling with changing from specializing in low-tech desert conflict to a focus on “great power ” competition with China and Russia.

“The National Defense Strategy is clear : We’ve got to build a more lethal force, ” Army Gen. Richard Clarke, who’s in charge of Special Operations Command, said at the conference. “We have to continue to foster our allies and grow more partners and we’ve got to reform; in the case of SOCOM we’ve got to reform to meet those threats.”

He added that “we still need guys that can kick down the door, that can shoot well, can jump out of airplanes. … But we need coders. We also need leaders who can apply ” artificial intelligence, the report said.

US Navy SEALs are trained to attack enemy coastlines and ships, wreaking havoc on targets both on land and afloat, Popular Mechanics reported. SEALs typically disembark from nuclear attack submarines miles from their target, taking what’s called an SDV to their destination.

The SDVs are strictly utilitarian, even lacking windows for seeing outside the submersible. The ride is best compared to a small car or airplane, with no room to stand, no room to lie down, and no bathroom.

SEALs wear wet suits and rebreathers, breathing the vehicle’s onboard oxygen supply to keep their own tanks topped off, Popular Mechanics reported.

Unlike most submersibles, which use nuclear or diesel electric power, the SDVs use electric motors fed by onboard batteries for propulsion. The electric motor drives a single propeller, with the driver controlling the depth and direction of the boat via hydroplanes and rudders.

Departing from a nuclear attack or cruise missile submarine mothership, a small group of SEALs could motor to a stretch of enemy coastline and then stage a reconnaissance mission or raid inland, Popular Mechanics reported.

Alternately, they could slip through enemy defenses, park their SDV outside an enemy harbor, and then proceed one by one to plant limpet mines against the hulls of enemy ships.

Naval Special Warfare said it doesn’t talk about its manning in Hawaii for security reasons, but the Defense Department comptroller’s office said that as of 2018, the command had 525 personnel at Pearl Harbor.

A US$54.3 million contract was awarded in April, meanwhile, for a Naval Special Warfare undersea operational training facility at Pearl City Peninsula with an undersea vehicle training tank, the report said.

The future Virginia-class attack submarine USS Delaware (SSN 791) conducts sea trials in the Atlantic Ocean. U.S. Navy photo courtesy of Huntington Ingalls Industries by Ashley Cowan /Released.