Skąd. Shaw był posiadaczem trzech rebreatherów: BI, Cislunara i Mk.15.5. Tego ostatniego używał do nurkowań głebszych niż 150m, BI uzywał do głebokości 150m. Całość operacji była przeprowadzona tylko na obiegach zamkniętych. Jeden Mk.15.5 i co najmniej 10 BI.

Shaw już kiedyś miał problem z HPNS na głębokości -213m, co zresztą opisywał (problemy ze wzrokiem, widzenie tunelowe). Podczas poprzedniego nurkowania na -271m wszystko było OK, jednak jak widać tym razem nie.

Zanurzał się z prędkością 30m/min

Tak naprawdę żadne z urządzeń nie jest dostosowane do nurkowań głębszych niż 150m również Mk15.5 który jest modelem z roku 1975! Jego podstawowe zastosowanie to rozminowywanie podwodnych pól minowych. Więc zawsze jest to bardziej loteria.


Z południowo afrykańskiej gazety (nieco długie):

09 January 2005 10:11

In a thick Australian accent, Dave Shaw's first words to me on Thursday evening were: "How you doin', mate?"

He reminded me somewhat of Captain Haddock from the Tintin comics. He smiled briefly but seemed focused and pre-occupied with the task that awaited him two days later. He would be diving to a depth of 270m to attempt to recover the body of Deon Dreyer who drowned at Boesmansgat in December 1994. He never returned.

The next day a relaxed and confident-looking Shaw showed us the rebreather he would be using on his descent into Boesmansgat on Saturday morning. Unlike conventional scuba diving gear, rebreathers recycle exhaled gas by chemically scrubbing it of carbon dioxide with soda lime. Thus diving on a rebreather is bubble-free, less wasteful of gas and allows more dive time. It was stowed away under a ledge several metres from the water's edge. It was a non-magnetic Mark-15 Five, because it had originally been designed for use by Navy divers when defusing mines.

Talking to him, I had the impression that the dive had already been successfully concluded. He showed us the knife he would be using to free Deon Dreyer's body of his gear. He said he did not foresee any problems. His thermal underwear hung from a tree branch. He would be wearing it under his dive suit to help him stay warm at the extreme depth where the temperature was as low as 18C. He showed us his two 10 watt lights, each with a battery pack lasting four hours.The mixture of gases he would be breathing was regulated electronically. There were further electronics to back those up in case of a malfunction. Shaw also had the option of switching to manual in case of an emergency.

Despite all of these precautions and calculations, something went wrong on Saturday morning. Shortly after 6am, Shaw's team mate Don Shirley descended to 250m to look for his light but saw nothing.

Around 9am on Saturday, Andries van Zyl, the owner of the Mount Carmel farm on which Boesmansgat is located, drove to where reporters were waiting. He stopped and looked at us in silence for a few moments. He shook his head."The shit has hit the fan," he said. "Dave's not coming up."

The Star reporter Jonathan Ancer's face froze. I felt a knot in my stomach. For several minutes I hoped Van Zyl had been misinformed or was exaggerating. As the day wore on, police officers told us that "things were going to plan" and "things are very bad down there".

Perhaps Shaw wanted to retrieve Dreyer because he wanted a challenge. Perhaps he wanted to help the Dreyer family overcome their loss. Perhaps it was a combination of both.

The third deepest freshwater cave in the world lies at the end of a 10km stretch of dirt road on the farm Mount Carmel, 50km south of Kuruman. In the middle of the veld, a large crater about 50m deep tapers down to an opening only a few metres wide.

On Saturday, a team of volunteer technical divers and police divers, assisted by paramedics, attempted to recover Dreyer's remains.The divers entered the 18C water at 6.15am. Thirty minutes later things began to go wrong. Shaw, who was to dive to the bottom to secure Dreyer's remains failed to meet his team mate Don Shirley at 220m. Shirley, the dive's technical coordinator, then descended 250m in an attempt to look for Shaw but began suffering from decompression sickness.

Vomiting and disorientated he returned to the surface around 4pm on Saturday and was placed in a recompression chamber. Shaw was not seen again.

According to the plan, it would then have taken Shaw 11 hours and 50 minutes to return to the surface, cold, exhausted and hungry, having sipped only water and energy gel for 12 hours.
"On the bottom, time is critical," Shaw said on Friday.
At 270m, every second would add one and a half minutes to the time it would take him to re-surface.

"This is an extreme dive. I am repeating a world record dive with a task at the bottom," Shaw said