Reporting from the "Graveyard of the Pacific"

This week on 60 Minutes, correspondent Bill Whitaker reported on the surfmen , an elite unit of the U.S. Coast Guard.

These steel-nerved men and women train in a dangerous inlet near the coastlines of Washington and Oregon that has earned an ominous nickname: the "Graveyard of the Pacific"— and for good reason.

The broad, fast-moving Columbia River and waves that have been traveling across the Pacific, all the way from Asia, collide here. The chaotic surf has wrecked thousands of ships and sailboats over centuries.

• U.S. Coast Guard trains elite rescuers in dangerous area called "Graveyard of the Pacific"

Certified surfmen are expected to perform daring rescue missions in waters like these, with waves that can be as high as 20 feet and winds up to 50 knots.

Whitaker and the 60 Minutes team wanted to climb aboard a 47-foot lifeboat to see how these surfmen train for one of the Coast Guard's toughest assignments.

But before getting on board, the team needed to test a dry suit, a waterproof suit that retains body heat and prevents hypothermia if its wearer falls into frigid water.

On a cold morning in February, Whitaker tested his suit for leaks. Accompanied by two Coast Guardsmen, he submerged himself in the icy water of the Columbia River for 15 minutes.

"I had no protection on my hands. And I'll tell you, my hands were freezing. But the dry suit kept my body relatively warm," Whitaker told 60 Minutes Overtime.

Whitaker and the team were given a safety briefing before they headed out on the lifeboat. They were told to prepare for the possibility of a "rollover," when a wave crashes into a boat and sends it spinning 360 degrees on its axis.

While driving the lifeboat out into the inlet, Chief Instructor Eric Ceallaigh explained how the boat's design prevents it from sinking in the event of a rollover.

A large buoyancy chamber, and other compartments filled with air, allow the boat to pop back up if it's flipped upside down.

"Imagine you put a football in the bathtub…you push it down, the laces always shoot up," Ceallaigh said.

"So, as this boat gets underwater…it's going to violently re-right itself, to where we can get ready for the next wave."

Whitaker told 60 Minutes Overtime that to prevent him and photographer Dennis Dillon from getting tossed into the sea during a rollover, they had to be clipped into two points of contact. They were told they would have to hold their breath until the boat re-righted itself.

"The whole rollover usually takes from eight to 12 seconds…we would have to hold our breath for that amount of time," Whitaker recalled.

"We'd be wet and gasping, but we would be safe and secure."

Out on the crashing waves, Ceallaigh and the other surfmen-in-training shouted out when they spotted a wave coming towards them.

Ceallaigh accelerated and steered the boat to maneuver, or even crash through, waves coming from all directions.

One technique called "squaring up," involved pointing the bow of the ship at the crest of a large breaking wave and accelerating over the top of it.

"You end up going way up onto the top of this wave… you look up, and all you see is sky," Whitaker explained.

"Once you get over the crest of the wave… you're looking straight into the water. And you're just being bounced and pushed around. And it really is the most incredible rollercoaster you could ever imagine."

Whitaker wondered how Ceallaigh could be so calm in such a chaotic environment and asked if he enjoyed it.

"If you let me go take… [a] lifeboat out into the surf, I'm immediately in the best mood," he told Whitaker.

"Full of endorphins. Happy as can be. All of my problems go away…I absolutely love it."

The video above was produced by Will Croxton. It was edited by Sarah Shafer Prediger.