Inside a non-descriptive building in South Florida is a very covert group like no other. Channel 4's Scott Johnson and Channel 4 crime and safety analyst Ken Jefferson recently returned from an unprecedented look at how Federal Air Marshals train to keep you and your family safe.

You can call the Federal Air Marshal program a secret world because the men and women stay hidden and specifically train to blend in. They sit with you in the terminal, board the plane with you, even protect you on the ground when you'd never expect it.

As news stories break, like with the "Underwear Bomber," the "Shoe Bomber" and most recently the Boston Marathon bombings, you hear about the FBI and other Federal agencies, but seldom do you hear about Federal Air Marshals.

IMAGES: Federal Air Marshal training

"We've been termed as the quiet professionals, and that's the way we'd like to remain, the quiet professionals," said Supervisory Federal Air Marshal Steven Petrick.

On the first day at the training facility, Channel 4 was given access to a unique training tool, a mock airplane. It's important for Air Marshals to train with every possible scenario that can occur inside a plane, even at 30,000 feet. And there are hundreds of scenarios they are prepared for.

"Now you're in a long tube?" Johnson said.

"Absolutely," Petrick said. "It changes the game tremendously. As a police officer on the street, you can fall back and take cover. When you're in the tube, it's you and the bad guy."

Air Marshals can do all kinds of things inside their mock airplane, even fill the cabin with smoke, make sounds and cause the lights to flicker in and out of darkness.

"We'll have other Air Marshals in here participating in the training. And that adds to the realism for the Marshals that are actually acting," said Nate Gulick, acting assistant supervisory Air Marshal in charge.

The agency was started in the 60s to handle an increased amount of hijackings. It fell under the Federal Aviation Administration. But at the time, there were only a few dozen Air Marshals in the country. It wasn't until Sept. 11, 2001, that all changed. Following the terrorist attacks, the Federal Air Marshal Program was moved to the Department of Homeland Security.

Petrick was a sheriff's deputy in Pinellas County.

"[I] had dreams of Secret Service, FBI, and then Sept. 11 happened," he said.

Petrick sent in his application overnight when he heard the Air Marshal Program was expanding to hundreds of Air Marshals around the county. He's been with the program ever since.

Petrick and his fellow Air Marshals have trained tirelessly to help prevent similar attacks from happening again. And if something were to happen and an Air Marshal needed to take action in the air, they train to protect the plane and the passengers.

"A child pops up, someone gets in your way. People are screaming. That's why we train so much and so hard," Petrick said. "We try to throw in every scenario possible just so when that comes, we're ready."

But you won't recognize the Air Marshal sitting on your flight. They are also trained to blend in.

"You've got passengers who probably want to chat, bump over luggage and kids. How do you prepare for that and make sure no one knows who you are?" Johnson asked.

"We train hard," Petrick said. "The men and women of the Air Marshal's Service are professionals. It's what we do."

Air Marshals are also the best shooters in the country. They have higher marksmanship scores than any other agency, including the Secret Service and the FBI.