Exploring the Depths: Tragedy Strikes in Australia’s Underwater Cave(The Shaft)

Exploring the Depths: Tragedy Strikes in Australia’s Underwater Cave(The Shaft)
Incident LocationDiver Full Names
South East Australia, The ShaftStephen Millott, Christine Millott, Gordon Roberts, John Bockerman

Nine divers went diving into a shallow-entrance cave called The Shaft, where many of them came into trouble when diving at greater depths than planned and struggled to get back to the surface.

The Discovery of The Shaft

As far back as 1938, in Thompson’s Paddock, a cave was discovered on farmland close to the eastern part of Allendale, some kilometers south of Mount Gambier, Australia. The name of the cave is “The Shaft.” It was discovered when some horses were grazing on the field and one of them slipped over a hole of about 1 ft (0.3 m).

For the sake of further exploration, the surface of this newly discovered hole has to be widened to about 3.3 ft (1 m) in diameter. It was never known that it was an opening to a larger underground cavern until divers began to explore it. A local diver came to this field in the mid-1960s, and to his greatest surprise, as he descended the small hole, he arrived at a wide lake cave with a depth of about 56 ft (17 m).

He began to go deeper until he reached a depth of about 69 ft (21 m). The main cavern is about 460 ft (140 m) in length and has a width of about 260 ft (80 m). If you enter the cave, the water level is mostly about 23 ft (7 m) below the ground level. There is a rock pile down there inside the cave; you will see it directly under the cave’s entrance.

Two tunnels extend further into the cave from the area around the rock pile. To the east, the tunnel is about 407 ft (124 m) deep, and to the northwest, the other tunnel is 260 ft (80 m) deep. If you go to “The Shaft” to dive, it is not like other caves where you can go in together with your equipment; you and your equipment have to be separately lowered down into the cave with a lift system.

The exploration and mapping that was done between 2002 and 2003 showed that the eastern tunnel had some barriers at about 187 ft (57 m) that limit further exploration into the cave. But if you can go beyond the barrier, the tunnel extends to a depth of about 407 ft (124 m). From this point, the tunnel becomes horizontal and is blocked by another rock pile.

The Tragic Dive

The name “Shaft” was claimed to have originated from the sparkling shaft of sunlight that reflects on the ground from the surface during sunny days. On May 26, 1973, a team of nine divers came for a cave diving adventure at “The Shaft.” The divers were Christine M. Millott, Glen Millott, Stephen Millott, John H.

Bockerman, Larry Reynolds, Gordon G. Roberts, Peter S. Burr, Joan Harper & Robert J. Smith. Joan Harper had told the other eight members of the team that she would stay above the surface while she prepared hot soup for them and helped them with any other things they needed of. So on May 27, 1973, the eight divers made a pre-exploratory dive into the cave.

The First Dive

They fixed a guideline from the entrance down into the cave to about 150 ft (46 m) into the water. They got to the rock pile that is directly under the entrance to the cave. It is a pile of limestone rubble that is 131 ft (40 m) high. They explored the circumference of the rock pile, after which they returned to the surface with the guideline they had earlier fixed to the entrance. The final exploration was scheduled for the following day.

Exploring the Cave

On May 28, 1973, the eight divers entered the water to explore the underground cave, as they had planned the previous day. They had refilled their cylinders at Mount Gambier. Within a short time, they got to the rock pile, which they had explored the previous day.

Safety Limits and Violations

Initially, they didn’t plan to exceed “the edge,” which is an extension of the main cavern whose slope is narrow and goes downward. The area beyond this region no longer has the natural light penetration that comes from the entrance. The rock pile happened to be the safety limit for recreational diving because the other parts of the cave are yet to be explored and are filled with silt and limestone debris.

Diving to a greater depth will cause divers to be more susceptible to nitrogen narcosis, except that they have a mixture of helium in their cylinders. The eight divers violated a lot of safety rules. Their guideline didn’t go far into the floor of the cave; they had no staging tank clipped to the guideline for decompression while returning; no gas management plan for their dive; and no predetermined diving buddy.

Unforeseen Depths

Glen Millott, one of the divers, later explained that going into such a narrow cave with eight guidelines might have posed greater dangers than they encountered. Robert Smith, who dove in this cave about eight times, said that he was not expecting the dive to have gotten to such great depths, especially for other members of the team.

Nitrogen Narcosis Effects

Robert began to feel the effect of nitrogen narcosis when he got to the base of the rock pile; nitrogen narcosis sometimes occurs in this region, but it is not as strong as going further into the cave. From his depth gauge, he discovered that he had already gone 180 ft (55 m) deep inside the cave.

Return and Missing Divers

Being a skilled diver and being acquainted with narcosis symptoms, he indicated to the other divers that he was returning to the top of the rock pile. Others indicated back to him that they were going further into the cave. After spending a few minutes around the base of the rock pile, Robert saw Glen coming from the passageway where he had seen others go, so they met at the rock pile.

Glen had kept an eye on the level of his air, and when he discovered that it had reached the limit to start returning, he turned back. While he was about to turn his dive, he sighted Christine. He was about to take her by the arm to inform her that he was returning to the surface, but she swam away before he could reach her. Both Robert and Glen returned to the surface together.

Surface Encounters

While getting to the surface, they saw Larry, who had surfaced before them. Just within the twinkling of an eye, Peter also surfaced with his tank almost empty. Glen immediately took up a spare tank and dove back into the water because he knew that the remaining four divers would be running out of air.

He found Stephen’s torch and camera at a depth of 225 ft (69 m), and the visibility was almost zero because the area was already silted-out. Glen had to return to the surface because he couldn’t go any further due to the visibility problem. When he got back to the surface, he met an ambulance that the divers who were on the surface had called for because of the emergency.

Desperate Attempts

Peter also went back into the cave in the hope of finding any of them, but that wasn’t possible either. At this time, they all realized that the other four divers had no chance of surviving in the cave again. Robert and Larry saw both Christine and Gordon trying to get back to the rock pile from the depth they dove into.

But they dove straight up, thinking they would find a way out much faster since they would have been running out of air. Unfortunately, they found themselves in a dome with no exit. That was the only time Robert and Larry could see the two of them. John was also seen to be under a strong nitrogen narcosis attack, as he was seen just diving further down into the cave. Likely, he didn’t know he was going to die.

Search and Recovery Attempts

On May 29, 1973, the Police Underwater Recovery Team dove into the cave and got to a depth of about 200 ft (61 m). It was a short search operation because they’d reached their diving limits, so none of the divers’ bodies were found. On May 30, they continued the search, which also proved abortive.

So, the police had to go for scheduled training from skilled Naval officers, which will last for many months before they can return for the search. In the year following, on January 22, 1974, a television film crew came to the site for cave diving. They dove into different caves that were in the lower South East. So, the crew dove to a depth of about 50 ft (15 m) with a more sophisticated light, which turned the entire cave into broad daylight.

Recovery of Stephen’s Body

One of the crew members, from where he was, looked into the distance to see that there seemed to be a third person behind two of his two dive teams. They later found out that it was a dead body in a wetsuit. So, they returned to the surface and reported what they had seen in the cave. The following day, very early in the morning, the police divers came to the cave and dove to the depth reported by this crew.

They found the body lying there at a depth of 50 ft (15 m), and they hauled it out. After a dental record identification, the body was discovered to be Stephen Millott, whose torch and the camera were found at a greater depth during the incident. When the police returned from their dive to the surface at a depth of 180 ft (55 m), no other body of the remaining three divers was found.

Discovery of Christine and Gordon’s Bodies

On March 9, 1974, a team of divers, together with R. G. Trayner, went into the cave. They entered with improved diving gear, which could make the recovery more successful. Trayner saw a body at a depth of 185 ft (56 m). He discovered that it was not just one body but two, the second underneath the first.

It was later found out that the two bodies were those of Christine & Gordon, who was seen last diving together during the incident. They were found below each other; it must have been that they both held each other when they discovered that they wouldn’t escape the death that had knocked on their doors. The same day, as Trayner went further into the cave, about 20 ft (6 m) away from where others were found, he saw another body under a rock ledge.

John Bockerman’s Recovery

The body was discovered to be John Bockerman. Trayner returned to the surface because he was now running out of air and couldn’t even gather the bodies together at a place where they could conveniently bring them out, as he had initially thought. On March 10, 1974, the divers returned to the cave to bring the bodies out, but that wasn’t possible with all of their efforts because of the murky waters.

They suspended the operation until the next day. Lastly, Christine Millott and Gordon Roberts’ bodies were brought to the surface on March 11, 1974. They began to feel the symptoms of nitrogen narcosis at the depth where they found the other two bodies, so they had to return from the dive.

Conclusion of Recovery Operation

The body of John Bockerman was still lying 215 ft (66 m) in the cave when they aborted the recovery operation. The divers were given a month’s break to recover from the stress and for further training to prepare for the last recovery at “The Shaft” cave system. A three-day recovery operation was scheduled for the recovery of the last body.

On the first day, they went into the cave with guidelines to figure out the exact location of the body. On the second day, they rested from the possible effects of nitrogen narcosis. Though the effects could fade within a few minutes after surfacing. So, on the third day, they went back into the cave and recovered the body. They had symptoms of nitrogen narcosis on the two days they had the dive.

The recovery operation was successful because they used advanced equipment, followed safety procedures, and planned the dive well. It wasn’t until April 9, 1974, that they were able to recover the body of John H. Bockerman. His body had spent 11 months and 11 days in the cave since the accident on May 28, 1973.

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What is “The Shaft” cave?

“The Shaft” is a cave located in South East Australia, near Allendale and Mount Gambier. It was discovered in 1938 when a hole on the farmland was found, and subsequent exploration revealed a wide lake cave with a depth of about 56 ft (17 m). The main cavern extends approximately 460 ft (140 m) in length and 260 ft (80 m) in width.

What happened during the tragic dive at “The Shaft”?

On May 26, 1973, a team of nine divers entered “The Shaft” for a cave diving adventure. While exploring the cave, some of the divers exceeded the planned depth, encountering difficulties and struggling to return to the surface. Unfortunately, four divers, namely Christine M. Millott, Glen Millott, Gordon G. Roberts, and John H. Bockerman, did not survive the dive.

What safety rules were violated during the dive?

The divers violated several safety rules, including not extending the guideline far into the cave floor, lack of staging tanks for decompression, absence of a gas management plan, and absence of predetermined diving buddies. These violations increased the risks associated with the dive and contributed to the tragic outcome.

Were any recovery attempts made after the incident?

Yes, recovery attempts were made to retrieve the bodies of the divers who did not survive. The police and other divers conducted search operations shortly after the incident but were unable to locate the bodies due to diving limits and poor visibility. Subsequent recovery efforts took place on various occasions, eventually leading to the successful recovery of all the bodies between January and April 1974.

What were the measures taken during the successful recovery operation?

During the final recovery operation, advanced diving equipment was used, safety procedures were followed, and the dive was carefully planned. The divers entered the cave with guidelines to determine the exact location of the body. They took breaks to avoid the effects of nitrogen narcosis and successfully recovered the last body on April 9, 1974. The recovery operation demonstrated the importance of proper equipment, safety protocols, and planning in cave diving.

Patrick Broin
Patrik, a seasoned cave diver, shares his first-hand experiences and expert insights on the treacherous world of cave diving accidents.
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