SAN DIEGO, Calif. — The Coast Guard national security cutter Waesche stopped into San Diego for a brief pit stop to grab fuel and offload 18 tons of cocaine on Wednesday, and we got a sneak a peek inside.

Waesche just finished its patrol near Central and South America, where it seized cocaine and smugglers during seven drug interdictions. It brought drug seizures from fellow cutters still in the region as well, offloading 18 tons of cocaine to the DEA for destruction — worth about $554 million on the street.

"There is a lot of cocaine moving across the water," said Capt. James Passarelli, who originally hails from Phoenix, Arizona but has been serving in the Coast Guard for the past 25 years.

The Waesche went out for about two months this time, though it typically deploys for three. Nowadays, they are fed intelligence leads and use drones and maritime patrol aircraft to "push our borders out" to stop the drugs closer to where they are coming from, according to Passarelli.

Though smugglers are constantly adapting as the Coast Guard gets better. On this latest deployment, the Waesche seized a self-propelled submarine and a low-profile vessel that even the captain admitted was "very stealthy."

Business Insider was invited to tour the cutter with Passarelli to get an understanding of what the service is doing to stop drugs from getting to American shores. As the captain explained, it's a "whole of government story" that involves the Department of Justice, State Department, the US military's Southern Command, and DEA, just to name a few.

Here's what it's like inside.