Alameda Coast Guard ship instrumental in massive cocaine bust

ALAMEDA, Calif. (KGO) -- Armed with infrared, high-powered cameras, the U.S. Coast Guard caught a glimpse of something far off the California coast.

In ABC News exclusive video, a submarine-like vessel can be seen before the Coast Guard bust.

Semi-submersibles are the latest move by drug cartels to smuggle cocaine and heroin into the U.S.

"The volume of trafficking is way up and our seizure rates are also up as well, said Captain Craig Wieschhorstr, the commanding officer of the Cutter Stratton. "It's a very high-paced, high-intensity mission.

Alameda's Coast Guard Cutter Stratton spent 45 days in the area of the Eastern Pacific known as the "drug transit zone."

From their missions and others, more than 50,000 pounds of drugs were offloaded in San Diego Wednesday morning. It's part of a record-breaking year for cocaine seizures.

Attorney General Jeff Sessions spoke from the docks. "We want to put continued pressure on the cartels," he said. "Call on the American people to reject the drug culture, crack down on prescription drugs that often lead to opioid excess."

The Cutter Stratton went on 11 of the 25 missions. The captain says keeping the drugs off the streets is gratifying, but their work does have a big picture impact.

"The biggest value is we get to introduce these folks into the U.S. Justice System and our partners with the DOJ through discovery, trial, and sentencing are able to glean information into the operations and leadership of these criminal networks," Sessions added.

He says more than 600 suspected drug traffickers have been arrested so far this year.