The slap that nearly killed a prospective Navy SEAL happened at 10:09 a.m. on Oct. 12, 2017, in the Donnell Classroom inside California’s Naval Amphibious Base Coronado, 24 minutes after BUD/S Class 326 students handed out maps and compasses.

The instructor posted a land navigation problem on the board and students started figuring out an eight-digit grid solution.

“It is understood by the class that in response to map and compass questions, Class 326 will have the opportunity to challenge one another with penalties for less accurate answers,” according to an internal probe into a serious incident that was obtained by Navy Times.

Navy officials say “challenge bets” among SEAL students keep class fun and foster a competitive camaraderie, particularly during the third phase of training, which Class 326 had just begun.

The 33-year-old instructor helming Donnell Classroom had gone beyond burpees, pushups and dousing students before chow, the investigation determined.

Wrong answers to his questions led to students drinking “dip spit,” getting their heads shaved or forgoing food until they left for training in the Laguna Mountains.

But the “go-to bet” in his classroom was a slap, a witness later told investigators.

“I grew up with two brothers and we got into a lot worse situations than slapping each other,” he said. “I figured this was just a way to toughen us up.”

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A 19-year-old student challenged the classmate who sat in front of him to deliver the right answer. And the challenged student botched it.

While other candidates continued their work, the pair strolled to the front of the classroom and mounted a stage.

The challenger stood a yard apart and cocked back an open palm. The other student put his hands behind his back, his left cheek awaiting the blow.

“It was a good slap,” the instructor later told investigators. “I guess he caught him on the button.”

“It was pretty hard slap, but there was no attempt to seriously hurt him,” the challenger added. “It was two men standing up on stage just trying to get it over with.”

The slapped student stumbled. The sound of his head smacking the tiles of the concrete stage echoed through the classroom.

“(The student’s) skull strikes the stage with enough force to make an audible noise, causing many students who were not paying attention to the scene to look up from their maps and compass work,” the investigator wrote.

The man who lost the bet began to bleed out of his ear.

All names are redacted in the report provided to Navy Times, including that of its author, but the unidentified instructor saw his student was out cold.

He ordered classmates to fetch medical help.

Other students began filing into another classroom but the slapped candidate remained unconscious.

At first he seemed to respond to a sternum rub. Blood began pooling around him on the deck.

By the time medical personnel arrived, he’d awakened but was disoriented and combative, the report stated. They had to pin his arms as they eased him onto a backboard.

The senior medical officer at the scene later told investigators she couldn’t get a straight answer from the instructor or other sailors about what happened. At first, they told her he was just talking and fell, but that excuse segued into something about “playing around.”

“With so many different stories, I stopped the conversation and didn’t ask anyone any further questions,” she said. “I knew that this was likely going to be investigated, and with the accounts differing so widely, they were not going to be of help in providing appropriate medical care.”

Class 326 resumed their map and compass review about 15 minutes after the incident.

“What do you think?” an instructor asked the medical officer. “Just a concussion?”

“I responded, ‘no, that’s more than a damn concussion.’”

First reponders rushed the slapped student to a University of California San Diego Health emergency room, where physicians discovered he was suffering from a skull fracture.

Blood had oozed into the membrane between bone and brain. He was placed in a medically induced coma to control pressure caused by swelling brain tissue, which was pushing against his skull, threatening to suffocate the flow of oxygen.

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When the 29-year-old patient emerged from his coma two days later, he couldn’t remember the slap. Or anything about the day it happened. Or the day before that, and the day before that one.

It remains unclear whether the patient is still in the Navy or if the incident left him with permanent injuries. But when the investigating officer interviewed him a few weeks after his blackout he bore no ill will for the student who slapped him, saying they were “training to become hard men.”

He recollected witnessing other slap bets while in BUD/S, but they weren’t “as serious as my slap.”

“I figured if I ever got put in that situation, I would just take it and not have any hard feelings toward my classmates. I just don’t know what happened in my case," he said.

He told the investigator he could see slap bets “getting out of hand quickly” but instructors were supposed to make sure that never happened.

“There are some strong guys and there are some other guys that aren’t as strong,” he said. “I think the instructors were just going to put boundaries on it.”

In response to Navy Times questions, Naval Special Warfare Command officials blamed the incident on a rogue SEAL instructor who let students make slap bets that were forbidden by regulations.

“The incident was caused by an instructor’s failure to follow well-defined remediation guidance, not something inherent to the student culture as a whole,” command spokeswoman Capt. Tamara Lawrence wrote in an email to Navy Times.

But the probe raises questions about how long the tradition of slap bets had preceded the 2017 incident and whether SEALs and their students tacitly tolerated the practice.

Several instructors told investigators they’d witnessed slap bets when they were students. One of them recalled the wagers when he graduated in 2012 with Class 295.

The third phase tactics cell chief reported that he saw slap bets in the land nav instructor’s classroom just a few days before the student’s injury, the investigation states.

The officer in charge of third phase training told investigators “there were slap bets” when he went through BUD/S, but he was unaware that the practice continued and couldn’t recall any guidance from his command about it.

One instructor added that slap bets were considered safe and he never thought something like that could occur, a perspective repeated by the SEAL in charge of the land nav classroom.

“Slap betting has been going on since I’ve been in (the SEALs) and since I checked in,” said the instructor whose student ended up in a coma. “Almost every tactics instructor has been in the room where there have been slap bets.”

“We don’t make it mandatory for them to slap each other, it’s on them,” he continued. “If students ever said they didn’t want to do it that would be fine.”

After awakening from his coma, his student told investigators that instructors told classmates to "go easy, and just know you guys are not enemies, you’re teammates, and it’s just a little fun that we’re trying to have.”

When a SEAL student lost a slap bet in October 2017, he and a classmate went to the front of this classroom. The slapped student fell and fractured his skull, according to an investigation obtained by Navy Times. (Navy)

The investigating officer didn’t see slap bets as “just a little fun.” His report recommended that Naval Special Warfare Basic Training Command codify the kinds of challenge wagers that are appropriate for BUD/S.

In an endorsement letter attached to the report, the unnamed commander of the training program said that wasn’t necessary.

“This incident was caused by an instructor’s failure to follow well-defined remediation guidance,” he wrote. “A codified list of challenges will only serve to inhibit our instructor’s ability to effectively employ challenges while adding unnecessary volume to an already-clear instruction.”

He promised to take “appropriate disciplinary and administrative action” against someone in his command, but the redacted report fails to specify whether it was the instructor who allowed the slap bet during the 2017 incident.

Because the land nav instructor “was aware that a slap challenge could result in a student being knocked out, as he had previously witnessed students being knocked out from slap challenges when he was in training,” the investigating officer recommended he go before disciplinary and trident review boards for willful dereliction of duty and failure to obey a lawful order.

He also recommended a disciplinary review board for the tactics cell chief who failed to stop the slap bets he allegedly witnessed in the instructor’s classroom before the 2017 injury.

Turning to the commissioned officer and his lead petty officer in charge of third phase training, the investigator urged Navy leaders to convene an Executive Officer’s Inquiry to determine if the slap bet system under their watch was tantamount to negligent dereliction of duty.

A student at Navy SEAL basic training embraces the suck at Naval Amphibious Base Coronado, California, last year. (Petty Officer 1st Class Abe McNatt/Navy)

It’s unclear if Naval Special Warfare undertook any of the recommendations.

Lawrence declined to say who was disciplined for what in connection with the student’s brain injury.

While the investigator highlighted several potential Uniform Code of Military Justice violations in his report, Lawrence said “there was no cause to court-martial those involved.”

“We do not comment on administrative disciplinary actions or (non-judicial punishment) proceedings taken against any service member,” she added.

The instructor at the center of the incident is no longer assigned to SEAL basic training command but Lawrence declined to say whether he remained in one of the elite teams.

In his endorsement letter, the basic training CO wrote that the Class 326 members who hesitated telling the senior medical officer what happened would undergo “a discussion on the value of teamwork, dignified training, healthy competition, and judgement."

“While the student body within Class 326 may not be culpable in the incident itself, this will serve as an opportunity for them to contemplate their lack of judgement as a class in their failure to take action while participating in and observing blatantly inappropriate remediation techniques,” he wrote.

Lawrence said all classes are now taught by two instructors — instead of a solo SEAL — to provide “an additional layer of integrity to ensure policy is followed.”