SAN DIEGO -  

The crew of U.S. Coast Guard Cutter Morgenthau seized 4 tons of cocaine from smugglers off the coasts of Central and South America.

The U.S. Coast Guard and U.S. Navy seized the gigantic stash of illegal drugs as part of five open-sea operations in the last two months. All of those operations were off the coasts of Panama and Colombia, and 21 people were arrested. It's estimated to be a $100 million loss for drug cartels.

"So I think it has a significant impact to their wallet," said Drug Enforcement Administration Agent Gary Hill.

The drug busts have become old hat for the Morgenthau, as the crew has six major drug busts in its last five months at sea.

"For [the] Morgenthau, it’s becoming very regular," said Capt. Greg Burg, commanding officer of the Morgenthau.

Burg said the hardest part of the operations is getting the drug running boats to stop. A helicopter is often deployed to stop them.

"They’re relatively peaceful once they stop," said Burg. "Getting a vessel to stop at 40 knots is not the easiest thing to do."

When a bust is made, just like a World War II flying ace, the Coast Guard throws a sticker up on the side of the cutter. The sticker is of a snowflake for cocaine and marijuana leaf for pot.

"We have the stickers up there and because of this patrol, Morgenthau will be adding two more of the snowflakes for cocaine," said Burg.

Unfortunately, they don't have more stickers.

"There’s more getting through. We try to get as much as we can," said Burg.

The problem is the DEA, Navy and Coast Guard don't know how much gets through because when they do see something suspicious, they stop it.

"The amount that comes through is significant, but we seize a good amount," said Hill.

The DEA said it would take samples of the cocaine for evidence and incinerate the rest.