U.S. and Colombian security forces intercepted a semi-submersible vessel carrying about 10 tons of cocaine and arrested four people during a joint maritime operation, authorities said.
Officials said the so-called narco-sub was detected in international waters and tracked before being boarded by law enforcement teams.
The seizure is among the largest recent drug busts in the region and dealt a significant blow to trafficking networks that use semi-submersible vessels to move cocaine from South America toward Central America and the United States.
The four suspects were taken into custody for questioning and are expected to face drug trafficking charges.
Authorities said the vessel was designed to evade radar and patrols, a tactic increasingly used by organized crime groups to transport large quantities of narcotics across maritime routes.
U.S. officials said the operation was part of ongoing cooperation with Colombia to disrupt transnational criminal organizations and cut off cocaine supply chains.
Colombian authorities said the seizure reflected expanded intelligence sharing and joint patrols targeting trafficking corridors in the Pacific and Caribbean.
Officials added that investigations are continuing to identify the organizers and financiers behind the shipment.