The US Coast Guard intercepted a 40-foot submarine carrying over $165 million worth of cocaine in the Pacific Ocean earlier this month, authorities announced Tuesday.

Four drug smugglers were also arrested in the Sept. 1 bust by members of the Coast Guard cutter Valiant, who were on routine patrol in the Eastern Pacific when they detected the vessel carrying the powder.

After they detected the vessel, the Valiant crew dispatched two small boats with boarding teams to capture the submarine.

The crews discovered the vessel was carrying about 12,000 pounds of cocaine — 1,100 of which were safely recovered, authorities said.

The Colombian Navy arrived shortly after the initial bust and assisted.

It’s unclear exactly where the submarine originated from, but NBC News reported it was en route to the United States.

Valiant’s Commanding Officer Matthew Waldrom said in a statement, “There are no words to describe the feeling Valiant crew is experiencing right now.”

“In a 24-hour period, the crew both crossed the equator and intercepted a drug-laden self-propelled semi-submersible vessel. Each in and of themselves is momentous events in any cutterman’s career,” Waldrom said.