New London — A group of cadets stood huddled over a computer screen troubleshooting. They hadn't slept much in the past week and had consumed mostly junk food.

A few sauntered over to a table featuring a fresh box of doughnuts, then retreated back to their position. One cadet entered the room grasping a mug of coffee.

From Monday until Thursday, cadets at the Coast Guard Academy competed against other U.S. service academies and the Royal Military College of Canada in the annual Cyber Defense Exercise hosted by the National Security Agency. The U.S. Air Force Academy was the only service academy that didn't participate.

A core group of six cadets from the academy's Cyber Team, which recently received approval to become a sports team, did most of the competing. About 20 cadets from the academy's computer network security class also helped out.

During the exercise, which is carried out through virtual, private networks, each team sets up a computer network and an NSA "red team" tries to attack the networks.

Wednesday started out rough when the cadets discovered that overnight the red team had gotten into the firewalls of their computer network and reconfigured them to allow outside traffic to flow through.

"A lot of Wednesday was spent recovering from that," said First-class Cadet Caleb Stewart, captain of the cyber team.

Teams received points for keeping the NSA out, but also for keeping the services on their networks up and running. It's generally accepted that the NSA will be able to break in.

"The NSA, they're the best hackers in the world, so we weren't expecting to keep them out the entire time. We knew they would get in, but we're trying to stop them from propagating throughout our network the best we can, and when they do attack our machine, we're trying to stop them from taking as many points as they can," Second-class Cadet William "Trey" Maxam said.

The four-day exercise ended at 4 p.m. Thursday, and final scores were expected to be announced Friday at noon.

Maxam described the team's efforts on Thursday as "controlling the bleeding."

"So we're just trying to stop them from gaining more access to more machines, just trying to keep them in their corner," he said.

The academy's team was at a disadvantage against basically all of its competitors aside from the Merchant Marine Academy, because of its smaller size.

"When you have more people, you can keep an eye on more things, have more people respond to different areas simultaneously," said Lt. Grant Wyman, coach of the cyber team, describing how the cadets were stretched thin. Wyman is also an instructor in the electrical engineering department.

"We're not doing quite as well as we were hoping, but the cadets know why that is," Wyman said. "They have a lot of good lessons learned."

Most of the cadets who participated aren't graduating this year, so they'll be able to build on their knowledge for next year's competition, Wyman said.

At the end of the competition Thursday, the academy was in fourth place, though the final scores announced Friday afternoon will take into account challenges they completed before the live exercise began, so their ranking may change.

Vice Adm. Sandra Stosz, former superintendent at the academy, supports a cyber center of excellence at the academy and has been looking at the accreditation and positions needed to accomplish that.

Stosz stopped by Thursday morning to check on the competition on her way to a meeting in the area.

She's also interested in creating a pathway for cyber-inclined cadets to go to the U.S. Cyber Command or the Coast Guard's Cyber Command after graduating, and going through more schooling. She envisions it being a similar process to that of cadets who receive flight assignments, but first go to flight school.

j.bergman@theday.com