ABC News' John Muller reports:

Even as the plane she was piloting plummeted toward the frigid waters of the Hudson River, Denise De Priester Kok remained calm, cool and collected.

"I had faith in my skills," Kok told ABC News. "I had faith in God and I had faith in us as a team [that] together we are going to survive this.

READ MORE: 911 Call Shows Terror of Hudson River Plane Crash

Kok's "teammate" in the plane was her only passenger, Chris Smidt, 43, of Colonia, N.J. He and Kok, 39, of East Windsor, N.J., had just departed from an airport in New Jersey on a sightseeing tour around 5:00 p.m. Sunday when their Piper PA-32 plane began experiencing engine failure.

As the pair flew over the Hudson River, somewhere near the George Washington Bridge, the plane began to descend, dropping 400 feet in five seconds, according to WABC-TV.

"I was focused like a robot on the landing because it was dark and difficult," Kok said.

The commercial pilot and certified flight instructor landed the plane smoothly in the Hudson but soon she and Smidt faced another problem. The plane began to fill with water.

"We're in the water now but it's filling up so we're going to have to bail," Smidt told rescuers in recently released 911 calls. "We're going to the rear of the plane. The plane is filling up."

Kok and Smidt abandoned the plane and plunged into the Hudson. Wearing life vests, they were able to survive nearly 30 minutes in the freezing water before being rescued.

"My adrenaline was spiking so much I was just swimming like I was in the tropics," Kok said, all the while keeping her calm.

"There wasn't one second that she wasn't positive and kept me going," Smidt said. "Her training took over right away."

Kok and Smidt were spotted by a rescue boat piloted by an off-duty police officer who, along with his 12-year-old son, pulled the pair to safety.

"My dad has always told me to be brave and never be scared of helping someone," said the 12-year-old, Danny Higgins.

Kok and Smidt were treated for hypothermia at a nearby medical center and released. The National Transportation Safety Board is investigating the cause of the crash.