The Marine Corps took out a moving ship by firing a Navy missile at it from the back of an unmanned vehicle on land — a new weapon the service’s top general says will make “an adversary think twice.”

Commandant Gen. David Berger revealed new details about a groundbreaking test announced last month in which Marines in California used a deadly new system to take out a threat at sea. Known as NMESIS, the Navy Marine Expeditionary Ship Interdiction System can launch naval strike missiles from the back of a modified Joint Light Tactical Vehicle to destroy targets.

Berger said the Marines testing the system were able to sink a ship on the move near California. The Marine Corps’ top priority in the 2022 budget, he added, will be ground-based anti-ship missiles.

“A very successful test,” the commandant said Thursday during the annual McAleese defense conference. “… That’s conventional deterrence because that’s a capability that makes an adversary think twice.”

The Marine Corps is undergoing massive reform after two decades of ground warfare in Iraq and Afghanistan. Berger’s Force Design 2030 plans call for the service to ditch heavy legacy equipment, such as tanks, to prepare for lighter, naval-based missions. The plan is largely centered around threats Chinese forces pose to the U.S. military.

Emanuel “Manny” Pacheco, a spokesman for Marine Corps Systems Command, said the missile flew an attack path “that exceeded 90 nautical miles before impacting the target.” He declined to provide details on additional tests, but said others have been successful.

“The Marine Corps is investing in technologies and capabilities to modernize the Corps and ensure we maintain our competitive edge,” Pacheco added.

Berger said Thursday that Marines will have to support the Navy not only with anti-surface missions to take out enemy ships, but submarines too. The Marine Corps will need to step up to help control straits and other maritime avenues the U.S. and its partners and allies need open, he added.

“Littoral warfare is where you expect the Marine Corps to come on strong, and that’s where we’re headed,” he said.

Tanks and short-range towed artillery pieces aren’t a good fit for Marines to meet future threats. Instead, Berger said, they’ll need long-range fires and light amphibious warships.

“We are reorienting from a ground, sustained land-forces mode — which we’ve had to do for the nation for the past 20 years — into a naval expeditionary maritime mode,” he said.