MAY95-A 32-year-old cave diver is believed to have overexerted himself, narked out and drowned during a 200 f/61 m-plus air dive in an open pit iron mine quarry. The diver had separated from his partner during a deep air class dive that was planned for 150 f/46 m.
The maximum depth limit of the four-person class was set at 180 f/55 m by the instructor, but the diver and his partner had apparently planned to "sneak off" and dive to 200 f/61 m. Visibility was about 20 f/6 m. The two separated from the class as soon as the dive began and the instructor remained with the two "weaker" students. The pair then traveled close to 500 feet in doubles and twin stage bottles in 12-14 minutes in order to reach the deep section of the quarry, several hundred feet of which was beyond 180 f/55m. The surviving diver then turned the dive, thinking his partner was with him. He ascended to about 160 f/49 m, realized his partner was not following, descended back to 190 f/58 m, and tried to signal to the diver with his light. But the two had lost contact. The partner was found drowned at 213 f/65 m with gas in his tanks. Calculations suggest the diver was breathing at about 2 cf/min surface equivalent. Reportedly, the deceased diver had abandoned his partner during a previous class dive and had a reputation for wanting to go deep.
Matterhorn, offshore Channel Islands, California
JUN95-A cave diver, 7-8 minutes into his dive at approximately 300 f/92 m-plus on the Matterhorn seamount, apparently drained his 72 cf stage of trimix and switched back to the air in his doubles, and shortly after, rocketed to the surface, where he died of a massive embolism. It is not known if a convulsion proceeded his rapid ascent, though there was bruising at the back of his head. His computer showed 11 minutes of bottom time with a one minute ascent.
The diver, who was not mix certified but had some mix training and had supposedly made mix dives, was last seen swimming off the anchor line at 300 f/92 m by his two dive partners, who turned their "air" dive at 250 f/77 m (PO2 = 1.8 atm) to complete their decompression. Contrary to the dive plan, the diver reportedly left his two partners at 250 f/77 m, descended to 300 f/92 m, and swam off the line horizontally, where his partners lost sight of his bubble trail. He was later spotted at the surface, and his body was recovered. The team made the dive from a 25-foot inflatable approximately 25 miles off shore. The deceased diver’s girlfriend, who was not able to operate the vessel, was the only one on the boat during the dive.
Offshore Broward County, Florida
A 27-year-old diver never returned from a deep air dive to 450 f/138 m. The dive was a practice run for his attempt at a 550 f/169 m deep air record scheduled for this summer. Prior to his fatal dive, the diver reportedly had completed twenty air dives beyond 400 f/123 m, with a maximum depth of 480 f/147 m. The current record is 513 f/156 m held by Dan Manion (US). It was reported that members of the local technical diving community-many of whom practice extreme deep air diving themselves-tried to discourage him from attempting to set the record.
The dive was scheduled during the surface interval of a recreational, two-tank dive. The diver wore a single large-volume cylinder and an oxygen pony for decompression. The crew rigged a descent line, and the diver went over the side while the boat’s recreational divers looked on. The diver had no in-water support team.
About 7-8 minutes into the dive, a crew member jumped into the water, free-dived down, and reported that he saw bubbles. The crew member then pulled on the line in a pre-arranged signal to ascertain if the diver was okay. The diver supposedly returned the pull signal. About 20 minutes later with no sign of the diver, the captain sent down another diver to 100 f/33 m to look for him. There were no bubbles. He was not seen again.
Thunderhole Cave System, Florida
JUL95-A highly experienced cave explorer suffered an oxygen convulsion at 80 f/25 m and drowned after mistakenly switching to an EAN 50 decompression mix (50% O2, bal N2) instead of an EAN 32 at 120 f/37 m (PO2 = 2.3 atm) following an extended trimix dive beyond 200 f/61 m.
The diver and his partner were conducting a trimix dive which utilized two nitrox mixes (EAN 32 and EAN 50) for decompression. Reportedly, the bottles and regulators were numbered but not marked for depth, and the diver matched the regulators to the wrong cylinders during set-up. The diver then staged the EAN 50 mix at 140 f/43 m [EAN 50 has a "maximum operating depth" (MOD) of 72.6 f/22 m at a PO2 of 1.6 atm] instead of the EAN 32 mix, which was staged at 70 f/21 m. During decompression, the partner heard the diver's scooter kick in, and looked over to see the diver convulsing at 80 f/25 m. The partner freed the diver from the scooter, but was unable to save him. With no support or safety divers, it wasn’t possible to get the diver to the surface and resuscitate him.
A non-technically trained father and his 14-year-old son ran out of gas and drowned while trying to free the anchor on a wreck dive on air to the Moody at 130-140 f/40-43 m. A third diver ran out of gas, surfaced unconscious, and was revived. Two other divers on the trip were bent after they shortened their decompression.
The anchor line snagged following the first dive on the wreck, and five individuals on the boat decided to dive the Moody a second time instead of cutting the line and going to dive another, shallower wreck. The father, who organized the trip, partnered up with a second diver and decided to include his 14-year-old son, who had not yet dived that day. The father wore a dry suit and twin steel 72s with a single outlet manifold (no first stage redundancy) that were not overpressurized. The second dry suit diver wore doubles and carried a pony. The son wore a wet suit and carried an aluminum 80 cf tank. Reportedly, the team carried no decompression gas. Visibility was said to be about 50-60 f/15-18 m , water temperature on the bottom was about 50-55° F, and there was a strong surface current that nessesitated running a leader line from the stern to the anchor line to assist the divers’ descent. A second team of two divers followed the three down.
After descending and working to free the anchor line, the father’s partner surfaced about 8-9 minutes into the dive and told the captain they needed more slack to free the line. He then went back down to the bottom. Upon his return, the father indicated he was low on air and headed up the anchor line. The second team of divers also ascended. The son and the partner remained.
About 12-15 minutes into the dive, the son indicated that he was out of air. The partner gave him a second stage and the two started up. During their ascent, the partner ran out of air, switched to his pony, and tried to drag the son, now presumably drowned, up the line. The partner then ran out of air in his pony. In the process, he apparently dropped his weight belt before ascending unconscious to the surface. The son's body, being negatively buoyant, drifted back down. It is believed that the father either witnessed this event from the anchor line or saw the partner ascend alone, and went back down to save his son. The father and son were found together on the bottom.
correction
In the incident report last issue from Mayan Cenote, Mexico, we have two clarifications: (1) It is not known whether or not the deceased divers actually made it to the end of the A line. (2) The recovery team, not the divers from the original group, re-enacted the dive the following day.
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