Among the images of rescues following Hurricane Florence was a video of a Coast Guard rescue swimmer rappeling from a helicopter to investigate a truck caught in the flooding in North Carolina two days after the storm made landfall.

Rescue swimmers are a critical part of the response effort to hurricanes, flying around in helicopters in search of people who might be in danger.

It’s a job that starts with passing the Coast Guard’s 24-week Aviation Survival Technician School in Elizabeth City, N.C.

Brendan Davis, 30, a rescue swimmer who is going through Officer Candidate School at the campus of the Coast Guard Academy, said that of the 23 trainees in his class, only he and one other guy finished.

“It’s putting a lot of stress on you physically and mentally to make sure you can handle the stress because when you’re out there in the real Coast Guard, you’re out there by yourself,” said Erin Custer, 30, a rescue swimmer who’s also going through officer candidate school.

In addition to rigorous physical training, the would-be swimmers are put through endless survival scenarios in a pool with wind and rain machines that can simulate hurricane-like conditions. They’ll jump into the water and have to rescue instructors who are combative, pretending to be panicked survivors trying to get on top of the swimmer and out of the water, or practice hoisting a survivor up in a rescue strop or sling.

“If you’ve seen people getting picked up with just the swimmer and the survivor, that’s the strop. They’re using a strop. It’s the hardest test because they fight you the entire time,” said E.J. Richardson, 33, a rescue swimmer and officer candidate. “They’re fighting you for seven to 10 minutes. If you can pass that, you should be able to pass the school.”

If they graduate, rescue swimmers next go to emergency medical technician training in Petaluma, Calif. Then they become part of helicopter crews — first going on flights with swimmers who are already qualified — performing duties such as running the search cameras and some of the radio equipment, in addition to carrying out search and rescues.

Despite all this training, rescue swimmers still regularly come across situations they haven’t experienced before. Custer and Richardson both were part of the Hurricane Harvey response efforts, and said the flooding was unlike anything they’d ever seen.

“Full neighborhoods would be just roofs only,” Custer said.

He and Richardson emphasized that the worst place to go during these storms is an attic — unless you have a way out. During Harvey, helicopter crews had lines of axes “ready to go,” Custer said. That was a lesson learned from Hurricane Katrina.

Custer responded after mudslides swept across Santa Barbara County in California. Typically, rescue swimmers carry out search-and-rescues in open water.

“That was different than what we're used to,” Custer said. “Typically, our search and rescue is coastal — cliffs or beach line, off shore, in the waves. That’s what we’re used to and train for. Anything inland, same with hurricanes, that’s new, going down to houses, stuff like that.”

During the mudslides, Custer was part of helicopter crew that rescued a family — an  infant, two small children, their parents, and a Rottweiler and a pit bull — who’d been in their attic for nine hours. It was a prime example of why rescue swimmers, and search and rescue crews in general, have to be adaptable.

“Our pilots were hovering between trees and power lines — obstacles we typically don’t face,” he said.

There were too many unknowns with placing the rescue basket in the mud, which was littered with boulders and tree roots, so they decided to put it on the roof. The family was able to get to the roof through a window in the attic. The mom handed Custer the 6-week-old infant, “then everything started flowing,” he said. The crew dropped the family, including the two dogs, off safely at the Santa Barbara airport.

But often, it’s a job where you don’t know the fate of those you rescued.

“It’s lack of closure every time,” Richardson said, noting he’ll sometimes do a search on the Internet to try and find out what happened. “You just do the job, you hurry, do the best job you can, then you pass them off to the hospital. Then it’s off to the next job.”

j.bergman@theday.com