The U.S. Coast Guard in Northern California seized $181 million worth of cocaine in the largest drug bust of its kind, according to a statement released by the organization Wednesday.

The team raided a semi-submersible vessel carrying 16,000 pounds of narcotics 200 miles south of Mexico in the Eastern Pacific Ocean on July 18.

Approximately 4,000 pounds of cocaine, which the team purposely left in the vessel to stabilize it, was lost while towing the vessel so, authorities only seized 12,000 pounds.

Chief Warrant Officer Allyson Conroy said that the U.S. Navy maritime patrol aircraft notified the Coast Guard Cutter Stratton crew in Alameda, California after spotting something that looked suspicious in the water. The Stratton crew sent out its boarding team to that location, where it found the drug vessel.

A Coast Guard Cutter Stratton boarding team seizes cocaine bales from a self-propelled semi-submersible interdicted in international waters off the coast of Central America.

The Coast Guard Cutter Stratton crew is shown with cocaine bales seized from a self-propelled semi-submersible interdicted in international waters off the coast of Central America, July 19, 2015

The Coast Guard announced the historic seizure in a statement on Wednesday. All of the information in the drug bust had to be approved by various agencies the Coast Guard works with in the Eastern Pacific, which explains the delay, Conroy told Mashable.

Though this is the largest drug bust of its kind, the U.S. Coast Guard has disrupted 15 other drug smuggling attempts since April, seizing $540 million and 33,000 pounds of narcotics.