SEATTLE – Two Coast Guard divers killed in a botched Arctic training dive were loaded with too much weight and were assisted by untrained crew members who had been drinking beer, an official investigation has found.

The two divers, from the Seattle-based icebreaker Healy, plunged to about 200 feet – about 10 times deeper than intended – shortly after entering the 29-degree water on Aug. 17, 2006.

Coast Guard Lt. Jessica Hill, 31, of St. Augustine, Fla., and Boatswain’s Mate Steven Duque, 22, of Miami, were killed in the accident, about 500 miles north of Alaska. They were underwater for about 20 minutes.

Their asphyxia deaths were the result of a chain of mistakes, said Vice Adm. Charles Wurster, the Coast Guard’s Pacific area commander.

“Had any link been broken, this accident would not have occurred,” Wurster told a news conference Friday.

That included the untrained “tenders,” who were monitoring the divers from the ice above, and a lack of enough qualified divers to conduct such a training exercise, the report said.

It also included the “ice liberty,” which featured impromptu dips in the icy water, games of football and beer for crew members, and was held too close to the dive site.

Drinking was allowed during an ice liberty, with each person limited to two beers. But no records were kept about how much beer was consumed, which is against policy, Wurster said.

The investigation determined that Hill and Duque had not been drinking before their fatal dive. One of their untrained tenders reported having one beer, while another reported drinking three beforehand.

“The problem here was that the recreational activity was taking place at the same time as an operational activity that involves risk and specialized training,” Wurster said.

“It was the combination of the two things that lends an air to the whole accident event,” he said.

The Healy was sailing through the Arctic with about 35 scientists to collect data that would help them map the ocean floor. Hill was the ship’s dive officer, as well as the liaison between the scientists and the crew.

Hill’s father, William Hill Jr., did not immediately return an Associated Press call seeking comment on Friday. A number for Duque’s family was disconnected.

As Hill and Duque dropped beneath the ice, the untrained tenders above noticed that the lines connecting the divers to the surface were playing out very quickly.

Hill’s tender gave her line a series of single tugs, a signal to ask if she was OK. Hill responded each time with a single tug of her own. She was asking the crew to stop her line. But they believed she was responding “OK,” and let the line run.

Each diver was carrying about 60 pounds of weight when a normal load would have been 20 to 30 pounds, Coast Guard officials said.

The tenders later said they thought the divers were moving sideways beneath the ice, rather than straight down, when they saw the line reeling out, Coast Guard officials said Friday.

Shortly after the deaths, the Healy’s commander, Capt. Douglas G. Russell, was relieved of duty and reassigned to administrative tasks. His superiors cited “a loss of confidence in Russell’s continued ability to command.”

Russell and other officers in charge of the ship received official reprimands or admonitions, Wurster said Friday. Those actions could affect the officers’ careers in the future, he said.

“The captain had 8,000 days of excellent service, and he had one very bad day,” said Lt. Cmdr. Glynn Smith, a spokesman for Wurster.

The Coast Guard reviewed its entire dive program after the deaths and concluded that the quick growth of diving teams in recent years had outpaced the agency’s ability to provide proper oversight.

The Coast Guard initially ordered a safety stand-down of dive units after the accident and sped up its regular safety surveys. The Coast Guard plans more actions, including beefed-up training and inspection programs, officials said Friday.

“It is our obligation, to honor our lost shipmates,” said Rear Adm. David Pekoske, assistant commandant of operations.