Sea Drones Present Navies With ‘Back to the Future’ Problem: Paper

Navies are facing an old problem in a new form, defense and warfare experts argue.

Cheap sea drones armed to sink ships now allow foes to execute long-range naval attacks on warships at anchor, reviving a serious threat not really seen since World War II, a sweeping new CSIS report on the future of warfare says.

The naval warfare section of the Center for Strategic and International Studies’ new report calls this a “back to the future” moment for navies.

Section author Mark Cancian, a senior advisor, wrote that the emergence of uncrewed underwater vehicles (UUVs) and uncrewed surface vessels (USVs) as a threat presents new difficulties for global navies, particularly when their ships are in the same place for a lengthy period of time, leaving them vulnerable to attack.

Cancian explained that “a navy’s greatest vulnerability is in port when ships are stationary for an extended period and an adversary can execute a strike that requires time to plan and execute.”

In the Ukraine war, Russia’s Black Sea Fleet repeatedly learned this reality the hard way as Ukraine leveraged naval drones to devastate the Russian fleet and drive it away. In response to sea drones, Russia’s navy has been forced to build out port protections, strengthen warship capabilities, and boost patrols in an effort to prevent further losses.

The report pointed out that long-range naval threats to anchored warships is something navies haven’t necessarily faced since the Second World War.

During the war, Japanese mini-submarines launched attacks against ships in port at Pearl Harbor, Australia, and Ulithi Atoll. Some of these resulted in the sinking of ships. Italian mini-subs targeted the British anchorages in Egypt, and Germany’s U-47 slipped in and sank a Royal Navy battleship near Scotland.

With the rise of UUVs and USVs, now “navies face a ‘back to the future’ moment,” Cancian said, arguing that they will need to harden anchorages in a way that hasn’t been necessary since WWII.

Better protection for anchored ships is something the US Navy pursued after the short-range terror attack on the USS Cole in 2000. But these will need additions to adequately address the new, widespread threat of sea drones, Cancian wrote, and it’d be “better to do the next round of enhancements before an incident occurs.”

Those countermeasures can’t be too expensive for defense budgets or intrusive to operations, though, he added. It leaves some of the world’s biggest navies needing to adapt to a new problem quickly and effectively without breaking the bank.

On the flip side, UUVs and USVs also offer opportunities for navies as a tool for infiltrating adversary ports or defensive zones, surveillance and reconnaissance missions, and attacking enemy ships. Such weapons could be used in the waters around Europe or in those of the Pacific.

“Many navies face the problem of operating inside an adversary’s defensive zone. Surface ships have difficulty doing that, but uncrewed systems — which are smaller, cheaper, and more expendable — could,” Cancian wrote, explaining that NATO navies could target Russian ports and US allies could do the same to Chinese naval bases. But while there’s an opportunity for Ukrainian-style attacks, most navies are not looking at one-way attack sea drones yet.

Western navies like the UK, France, and the US are investing in USV and UUV capabilities, but they’re primarily for tasks like minesweeping and intelligence, surveillance, and reconnaissance or shooting and sensing.

The US Navy has no known programs for one-way attack drones. There is one UUV called Orca that’s capable of strike missions as well as reconnaissance and mine-laying, but it’s delayed by years due to technical difficulties, the CSIS report noted.

Orcas are also too expensive for one-way missions, Cancian explained, noting that they cost about $110 million each.

“US Navy shipbuilding plans envision hundreds of USVs and UUVs in the fleet, but budgets do not yet reflect that,” he wrote, and none are programs of record, meaning they haven’t been formally acquired by the services with allocated funding and construction plans.

This year’s reconciliation bill has about $5.3 billion dedicated to Navy uncrewed and autonomous systems, but questions remain about whether navies see a clear demand signal.

“Theoretical threats may drive some action,” Cancian wrote in the CSIS report, “but a successful attack outside the Black Sea would galvanize the target navy and provide another alert to global navies.”