 A patrol plane first spotted the submarine and informed the Coast Guard crew which then intercepted the submarine in the waters of the Pacific Ocean.
With the help of Colombia's NAVI, authorities apprehended four suspected drug smugglers and seized the cocaine.
"The joint boarding successfully stopped a drug smuggling vessel and also strengthened international relations and communications between the two partner nations," the Coast Guard said in a statement.
The “cocaine sub” mission included “search, maritime law enforcement, marine environmental protection, homeland security, and national defense operations,’’ The statement said.
According to local media, the four captured men are being prosecuted by the U.S. Attorney's Office in Tampa for possession with intent to distribute cocaine.Â
It is still unknown where the submarine is from.
