Ed.'s note: This regular column presents the anatomy of a diving accident and the lessons to be learned from it. The incidents described are real. Names of locations and people have been changed or deleted.
Jan and Alex were relatively inexperienced divers who had recently earned their advanced open-water certifications. While vacationing in a popular dive destination, they signed up for a morning charter to a wreck dive located a few miles offshore in deep water. The wreck rests in 120 feet of warm, tropical water and visibility is usually high, thanks to the swift currents that wash over the site. Depth and currents combine to make this a sometimes challenging dive that is recommended for advanced divers only.
When they arrived at the site, Jan and Alex's dive group found calm seas, 80-plus feet of visibility and an uncharacteristically mild current. The captain planned to place the divers on a moored line running to the bow of the wreck, allow them to swim the length of the wreck on the main deck at around 100 feet and ascend on a separate moored line at the stern of the wreck. Upon surfacing, the divers would find the dive boat tied up to the stern line mooring. Because the majority of divers in the group had little experience with this type of diving, they were cautioned to watch their air supply carefully, not to descend below 100 feet and not to venture inside the shipwreck under any circumstances. The dive began without difficulty and seemed to end in the same manner. After performing a post-dive roll call, however, the crew discovered that Jan and Alex were missing.
A crew member immediately descended to the wreck and started searching for the missing buddy pair. Swimming below the weather deck of the ship on the port side, he heard someone frantically banging on the hull. He moved to a porthole and peered inside the wreck where he found the two divers disoriented, hopelessly lost and extremely low on air. The rescuing diver was equipped with a pony bottle, which he removed and pushed inside to the lost dive team. He then quickly ascended to the surface to report the status of the divers and obtain more air. As quickly as possible, he descended back to the wreck with a partially filled tank. Because the larger tank would not fit through the porthole, he passed the second stage regulator and octopus through the opening for the divers to use. A crew member on a nearby charter vessel who was experienced in penetration diving was summoned by radio to assist with the rescue.
While waiting for the penetration diver, the first rescuer lost contact with Jan. His best attempts at communicating with Alex yielded no information about Jan's whereabouts or condition. He remained outside the wreck, securing the air supply and rotating it with new bottles shuttled from the surface as required.
The second rescuer soon arrived. He used a navigation line and carried staged gas for the lost divers as he penetrated below the weather deck, where he quickly located both divers in a small companionway. Jan was lying on the compartment's deck, unconscious, not breathing and completely out of air. The pony bottle found nearby was also completely out of air. A tank was passed to Alex, and he was directed to follow the navigation line out of the wreck while the rescuer retrieved Jan.
Jan was taken immediately to the surface where resuscitation efforts were started, while the rescuing crewman and Alex began extended decompression. Both rescuer and diver were inadequately equipped with exposure protection for this type of decompression and both of them soon began demonstrating severe symptoms of hypothermia. A decision was made to bring the divers to the surface and transport them to the nearest recompression chamber while administering oxygen.
By the time the divers arrived at the chamber, the rescuer was experiencing symptoms of Type II decompression sickness, and Alex was experiencing minor symptoms of Type I decompression sickness. Jan was pronounced dead upon arrival.
Alex's symptoms completely resolved after treatment in the chamber. The rescuer, however, left the medical facility days later with lifelong residual paralysis that could not be resolved.
What actually happened in the initial phase of this dive will probably never be clear. But it appears that Alex coaxed his girlfriend into the wreck to satisfy his curiosity about what was inside. Neither diver had any experience or training in this type of diving.
Silt and rust inside the wreck soon reduced visibility to only a few feet, and the divers became disoriented and panicked. Frantic swimming in an attempt to locate an opening further decreased the visibility and depleted their air supply. Fortunately, the rescuer swam by a porthole while Alex was peering out, allowing him to signal to the diver.
The rescuer, a full-time diving professional, placed his safety at dire risk in order to rescue the irresponsible pair of divers. His actions exceeded any expectation of his duty and saved Alex's life. By all accounts, they should have also saved Jan's life; no determination was ever made as to why Jan drowned while air was available for her to breathe.
Lessons for Life
- Penetration diving is an advanced form of diving that requires proper training, equipment and experience. No other single activity appears to result in as many avoidable diving fatalities as penetration diving by the untrained.
- When penetrating an overhead environment, assume that visibility will be reduced to zero, and use a navigation line that leads continuously to open water.
- Penetration divers should always carry adequate gas supplies to allow for emergency procedures, including adequate decompression gas when bottom times are unexpectedly extended.
- When diving with a buddy who decides to take reckless action, it is best to end the dive, even if that means signaling the buddy, aborting the dive and leaving him alone. Two fatalities are never better than one. Ultimately, you are responsible for your own safety.