Death of an Aquanaut
By Bill Bunton and Mary Heglar
17 February–April 1969—off San Clemente Island and San Diego
It was now 2 a.m. on February 17. The Robert Barth–Berry Cannon/Richard Blackburn–John Reaves team had spent the past five hours in the warmth of the deck decompression chamber (DDC), trying to recover from their nearly four hours in the numbing cold environment of the first dive. Barth and Cannon were additionally exhausted from heat loss and physical exertion. However, this was the more experienced pair, having trained in the entry procedure. The decision was made that they, and not Blackburn and Reaves, would have the better chance of gaining entry and quickly solving the leakage problems of the Sealab habitat on the ocean floor.
This would turn out to be a fateful decision.
Barth didn’t seem happy about going back down. He had complained of pain and difficulty in breathing during the first dive. Cannon didn’t say anything, but then Cannon seldom did, if it went against command authority; he was a good seasoned diver, with unshakable faith in the Navy’s ability to make the right decisions.
Bill Bunton did not know any of this when he left his duty station at midnight. But he was now deeply worried.
During Sealab II, the divers had been able to use Mark VI semi-closed-circuit scuba units that allowed the aquanauts the freedom of not being tethered to their breathing source. These units were not feasible at deeper depths because the tanks of helium-oxygen mixture carried on the divers’ backs simply could not hold enough gas to last any reasonable length of time. Although the tanks would be worn on all excursion dives from the habitat, their primary use would be under emergency conditions only.
The Sealab III solution for breathing-gas conservation was to use umbilical hoses between the diver and the personnel transfer capsule (PTC), and between the diver and the habitat. It was a workable system, in principle very much like that used in space walks, only heavier. But as the Navy was to discover only too soon, there was a difference between an umbilical suspended in weightless space and one dragging across the ocean floor.
An alarm bell rang in the communications van. It was now 2:50 a.m. The team of Barth, Cannon, Reaves and Blackburn already had received its orders for the second dive. During the interim they’d had hot soup, some rest, but little sleep—an hour at the most. As they prepared for their second descent to Sealab III, the flood gauge in the habitat sounded the alarm: Water had reached a depth of 6 inches.
At 3 a.m. the new gas barge arrived. The supply was enough for only 18 more hours at the present rate of loss. Nevertheless, Sealab command went ahead with its plan.
At 3:40 a.m., the PTC carrying the diving team detached from the DDC. At 4:13 it entered the water, and at 4:33 it reached bottom depth. Thirty-five minutes later, Barth and Cannon opened the hatch and swam out. At 5:08 a.m., Barth’s figure appeared on the TV monitor up in the van. Cannon could not be seen; he was working at the other end of the habitat, out of sight.
The TV camera’s floodlamps illuminated hundreds of fish against the black background of the water as Barth climbed the ladder to the diving station. Again he tried to push open the hatch that had been so troublesome on the earlier dive.
To the men topside, the picture on the TV screen was, at first, almost a replay of what had happened on the dive just hours earlier: Barth strained in vain, gave up and swam out of view. Then it became a drama they were watching on the monitor.
A squeaking voice from the PTC says Barth has returned to pick up a crowbar. The PTC is behind the habitat, hidden from the camera. The camera shows only the forward underbelly of the habitat, with the ladder extending down from the entrance hatch, and the sea bottom for 5 or 10 feet beyond. The water has turned murky because Barth’s trailing umbilical has stirred up the silt.
Barth reappears on the screen, the crowbar visible in his right hand. Suddenly he switches direction, swimming rapidly away from the camera, past the hatch and out of view to the right. His flippers stir up more clouds of silt.
“Holy shit...” The strangled words come from one of the men in the communications van. The others are silent, staring at the screen.
Barth reappears. He is towing something.
“It’s Berry,” someone whispers.
Barth is seen dragging Berry Cannon to the habitat support platform. He props him upright against the ladder, apparently trying but failing to get Cannon’s head within the skirt’s breathable gas pocket. Barth then attempts to give Cannon gas from Cannon’s emergency aqualung regulator. More clouds rise as Barth works, obscuring the vision topside. But in the van the aquanauts know what is going on: Barth is trying to push the mouthpiece between Cannon’s teeth.
“Get another diver in the water now and send him to the habitat!” The diving officer in the van snaps the order down to Blackburn and Reaves in the PTC. Acknowledgment crackles over the speakers.
Bob Barth continues to struggle, desperately trying to hold
Cannon up and force-feed him gas at the same time. Cannon is convulsing, and Barth is unable to push the mouthpiece between his teeth.
Eventually, the team leader gives up and swims off, dragging Cannon with him. They both disappear from view.
Suddenly Barth is back again on the screen, alone. As he reaches the ladder it becomes obvious why he returned: His umbilical cord is fouled in the ladder rungs. He doesn’t have enough free hose to make it back to the PTC. He labors to untangle it, his motions revealing that he is all but spent. Finally, he dislodges the umbilical, and with short, exhausted strokes he swims off in the direction of the PTC.
Berry Cannon is nowhere to be seen, even after the silt settles behind Barth. The aquanauts watching the monitor have no way of seeing that Cannon is lying only a few feet from the PTC. Barth, after freeing his umbilical snarl, doesn’t have enough strength left to pick Cannon up.
As Barth drags himself to the PTC, Blackburn, following the orders from topside, is just getting out. Barth is partially hauled inside by the remaining diver, Reaves. Seconds later, Blackburn is with Cannon. Blackburn, 6 feet 4 and built like a bear, assisted as much as possible by Barth and Reaves, picks up Cannon with both hands and thrusts him up through the open hatch of the PTC.
It is 5:15 a.m. Only seven minutes have elapsed since Barth first appeared on the TV monitor. How long Cannon has been in trouble, no one knows. It could have been the full seven minutes, or it could’ve been only three.
It doesn’t matter. At 610 feet, even one minute is too long.
The PTC reports by phone that Cannon is “in bad trouble.” Reaves and Blackburn try to revive him, first by forcing gas into his lungs and then by cardiac massage and mouth-to-mouth resuscitation. They continue their efforts as the PTC is being hauled up as fast as the winches can handle the load. During the ascent, Cannon does not regain consciousness. He is not breathing. His three comrades think he is dead, but they aren’t certain.
At 6:05 a.m., the PTC is hauled back aboard the Elk River and mated to the DDC. Cannon is placed in the DDC’s outer airlock. If he is still technically alive, he’s brain-dead and has been for nearly an hour.
No doctor on the outside can quickly enter the pressurized DDC without first closing the hatch separating the interlock, then venting the outer lock, then pressurizing it to the 610-foot depth. A second option is for Dr. James Vorosmarti, in the other DDC, to be transferred via the still-pressurized PTC just vacated by the Barth team.
Either way, it is far too late. From closed-circuit television and porthole observations, all concerned authorities, including medical officer George Bond, are certain Berry Cannon is dead.
Cannon’s body, still pressurized to 610 feet, couldn’t be brought to atmospheric pressure without gross distention from explosive decompression. But hours later the decision is made, and commencing at 9 a.m. he’s brought to surface pressure anyway, in the outer airlock.
Bunton didn’t see the body when it was removed. He didn’t need to.
Bunton couldn’t believe what he read in the newspapers the next day. The Long Beach Independent for 18 February 1969, under the headline “Diver’s Death Halts Sealab,” reported:
San Clemente Island—The nation’s most ambitious Man-in-the-Sea experiment, Sealab III, was postponed indefinitely Monday after one of the Navy’s best aquanauts died of an apparent heart attack in bone-chilling waters 610 feet below the surface.
In a shoreside interview, project manager Captain William M. Nicholson, tired and disappointed, announced suspension of the planned 60-day undersea venture.
Dead is 33-year-old Berry L. Cannon, a Navy electronics engineer who was the father of three boys.
Nicholson said the detection of several helium gas leaks in the 70-foot-long Sealab habitat was another factor affecting the decision to delay the project.
The [surviving] aquanauts in the deck decompression chambers (DDC) on the surface support vessel, the Elk River, are undergoing decompression—a process that will require them to remain in the chamber for approximately seven days.
Nicholson said the habitat was being readied to be brought back up to the surface, and “We will not resume diving until we learn what caused Cannon’s death.”
He said Cannon’s body was removed from the DDC through a lockout chamber and taken to San Diego Naval Hospital. “We do not know whether Cannon died as a result of making the dive or whether it was a coincidence that he suffered a heart attack at the very moment he was making the dive,” the captain said.
That made it all but official. Cause of death: heart attack. Other Navy personnel began to use the phrase themselves, as though it were fact. Two days after the tragedy, however, a Man-in-the-Sea spokesman told the press, “We have been informed that the gross autopsy was not conclusive. Laboratory tests are continuing.”
San Diego medical writer Cliff Smith was knowledgeable enough to interpret the statement. “This,” Smith wrote in the The San Diego Union, “seemed to rule out the possibility that Cannon died of coronary occlusion, the most common cause of sudden death and what is usually meant by ‘heart attack.’”
But by this time, the Sealab story had moved off the front pages of newspapers across the country. What most people remembered was the first-day story that in an unfortunate coincidence a diver had suffered a heart attack while he happened to be on the ocean floor.
Sealab III remained officially suspended pending the official board of inquiry. With proceedings closed to the press, the board convened in San Diego on February 28 and concluded on March 12. There, the truth came out: Berry Cannon had not had a heart attack. He died of carbon dioxide poisoning.
Someone had neglected to fill the carbon dioxide scrubber on one of the four Mark IX diving rigs previously placed in the PTC. Cannon, after his first few breaths, had been breathing pure poison—his own carbon dioxide–charged exhalations.
The scrubber was an aluminum canister hooked into the semi-closed-circuit breathing system. Before each dive it was filled with a fresh load of 8 pounds of baralyme granules. Each exhaled breath would pass through the canister, be cleansed of carbon dioxide by the baralyme and pass into a breathing bag. This bag in turn provided the diver with his next breath, supplemented by a small charge of fresh gas from the umbilical cord attached to the diving unit and connected to the PTC source.
Cannon’s canister proved to be completely empty. It had never been filled.
The four Mark IX diving units, each one supposedly set up, checked and rechecked by other aquanauts, had been placed inside the circular wall of the PTC. Upon entering the capsule, each diver grabbed the nearest unit.
One of the four divers that morning was going to die. That Berry Cannon was the one who’d taken the unit with the empty canister had been pure chance.
On February 19, a plane was chartered for 12 aquanauts—those who’d been closest to Cannon, including Bunton—to attend a memorial service in Chula Vista for their fallen comrade.
It should not have happened. Theoretically, it could not happen. There were too many safety checks in the procedure for setting up the rigs. But happen it did.
Who was to blame? Medical officer Bond’s anger and frustration was evident when he was quoted in the media as saying the project had been strangely “trouble-ridden” for more than two months before the fatal incident. He also told the press: “To my knowledge, never before has our program had anything like the sheer number of equipment failures seen in Sealab III. Malicious or otherwise, the gas leaks and other hardware mishaps were, to me, just unbelievable.”
The board of inquiry sat for almost two weeks yet was unable to pin down the responsibility. The official finding was death by carbon dioxide poisoning. No blame settled on anyone.
Bunton, like the rest of the once-elite corps of aquanauts, returned to his original job, at which he’d been promoted to diving supervisor. The day after the inquiry closed, Wally Jenkins phoned Bunton’s San Diego office from Panama City. They’d gone through Sealab II together and, had fate not entered the picture, would have been diving buddies again on Team Four in Sealab III. Together almost continuously for the past four years, and both being civilians in the Navy-run project, they’d become fast friends. Jenkins wanted to know what had taken place at the hearings.
Bunton sidestepped: “Didn’t the newspapers there cover it?” He was uncomfortable. Jenkins had been close to Cannon, too, and as an oceanographer, Jenkins had worked with Cannon for many years at the Mine Defense Lab at Panama City. Jenkins hadn’t attended the hearings because he’d been ordered back to Florida within hours of Cannon’s death.
“Sure they did, front page every day,” Jenkins said. “But that’s not the same as being there. You went, didn’t you?”
“Yeah, I had to. I was supposed to testify. They even told me to prepare a written statement. But they never called me to the stand.”
“The papers said the only disciplinary action was a letter of reprimand to [designated commanding officer Jack] Tomsky,” Jenkins said. “I know he had to get one; he’s the honcho of the whole affair and has the responsibility for whatever happens. Everyone knows it doesn’t mean a thing.”
“True,” Bunton agreed. “And we both know there were a dozen other aquanauts and boot-camp Seabees, recently recruited only some hours earlier, in and out of the diving locker area, helping out. Christ, you were there; you know how we rushed to meet the deadline.
“The Navy had told the press that Sealab III would start February 17, so that’s when they had to start. No more delays, no matter what the cost or how inexperienced the help. You saw the 13 sailors they dumped on us from the Naval Training Center—not one ever even had a mouthpiece between his teeth, and they were running
all over the place! But they were only kids trying to help, flown in at the last minute when everything turned to shit.
“The Navy couldn’t blame one of the Seabees. It wasn’t their fault. Everybody just had too many damn things to do at one time, especially in those last 36 hours.”
“But didn’t that come out at the hearings?” asked Jenkins.
Bunton’s voice dropped. “There were a lot of things that didn’t come out.”
Jenkins’ voice dropped, too. “Like what?”
“Like the fact that they roped off the DDCs the day after Berry died and put guards around them.”
“Jesus, why on earth would they do that?” Jenkins wondered.
“Because they found an open oxygen valve on the line leading up to the emergency BIB [built-in breathing] system in one of the chambers—while the guys were still in there decompressing.”
“An open oxygen line?” Jenkins sounded incredulous. “One day after the dive? C’mon, Bill. They must’ve only been at the equivalent of 400 feet into their ascent. Pure oxygen at that depth would’ve had them convulsing in three minutes, dead in 10!”
“They were lucky. Only the front valve to the main gas supply was open. The other one down the line was closed. And you won’t believe this: It happened twice.”
“You mean someone deliberately tampered with it?” asked Jenkins.
“Even worse. After the first time, that oxygen valve was wired closed. So somehow, someone broke the wire seal and opened the valve again. There was such concern that a 24-hour armed guard was stationed around both DDCs, and an officer had to ascertain the valve lineup every hour during the remaining days of decompression.”
Jenkins wanted to know more about the testimony, and Bunton sketched some of the highlights: the listing of the numerous mechanical problems, the screening of the videotape showing Barth’s fouled umbilical—and the lack of adequate deep-water training, the project’s most serious failure from the beginning. “Despite two weeks of hearings,” Bunton said, “they never did figure out who had neglected to refill the empty baralyme canister.”
“I guess it really doesn’t matter,” Jenkins said slowly. “What matters is the way they set up the system. Berry had no control over his own equipment. He had to rely on someone else.”
In Sealab II, each diver had usually set up his own diving rig. But in Sealab III, because of the usage of DDCs and PTCs, and because of the topside manpower shortage that forced continual rushing and little sleep the final 36 hours, rigging responsibilities went to just about any other aquanaut except the diver involved.
Promising to stay in touch, Bunton hung up. Then he rummaged through his desk for a paper he’d given on the problems of deep underwater photography. Captain Bond had asked him to present the topic at a symposium on “Man’s Extension into the Sea” in January 1966, after the completion of Sealab II. Bunton’s presentation was later printed in the symposium volume of technical papers.
Bunton scanned his article until he found the paragraph that was banging around in his head:
“...Saturation dives from a pressurized habitat ... can be dangerous because of the complexity of the self-contained units used for mixed gas. Unfortunately, the problems that can develop with this equipment are such that there is little warning, if any, and a diver must constantly be on guard for the slightest sign of a malfunction. In many instances, others may have set up his unit for him; this can be a disturbing thought. ... On a saturation dive, he now knows that in case of an emergency he cannot surface without meeting certain death. He can no longer take his diving apparatus for granted, and years of training and his own instincts are contradicted. This condition creates a mental hazard that burdens the diver’s mind and, in varying degrees, can detract from his functional capabilities...”
Bunton quietly closed the volume and put it away.
Sixteen years later...
“The entire Sealab project,” wrote Bill Barada in the September 1985 Skin Diver Magazine, “was constantly hampered and harassed by opposition from indifferent and incompetent Navy officials ... [After] the Navy bureaucracy took charge, decisions and procedures were dictated by Washington brass, and experienced Sealab personnel were ignored. The result was a long series of failures that ended in disaster.
“Cannon’s death was an excuse to abort the entire program. The project was mothballed, equipment and materials were stripped, and nothing remained of the $10 million Man-in-the-Sea program except a rusting steel hull.
“The high hopes and expectations of U.S. Navy aquanauts for a successful conquest of innerspace went down the drain.”
As harshly accurate as Barada’s summation may be, it also must be appreciated—and remembered—that this was a human endeavor. Humans make mistakes. Plenty were made in this program, as in all experimental programs.
Lives—brimming with promise and accomplishment and vigorous dreams—have been lost out there on the edge. The aquanauts all knew this and were still willing to accept the risks. To taste your own fear and apprehend the high risks—and still push past the edge...