Diving Beyond Personal Limits
Ed.'s note: This regular column presents the anatomy of a scuba 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.
Setting the StageMany dive sites in the northern United States and Canada offer excellent diving with wonderful underwater geography and a wealth of marine life. But these dive areas are often demanding, with cold, dark, turbid waters subject to fierce currents. And so it was, on a rainy, windy April day as four divers planned a wall dive in the 75- to 100-foot range. Water temperature was in the mid-40Fs with visibility lowered by river runoff.
The group included two young adult men who had rented their gear, including wetsuits, just for this dive and two middle-aged men with most of their own gear. Two of the divers had not dived for three years, one had just completed his entry-level certification course, and one of these inexperienced divers had only dived in the tropics. The one experienced diver was equipped with a dry suit, had dived the area before and was experienced in deep diving.
The two divers who had rental gear were unfamiliar with the BCs, particularly the use of them in cold water while wearing thick gloves, and were also unsure of how much weight to wear. In spite of the conditions, all four divers were eager to make the dive.
The Dive The continuing foul weather did not deter the divers during their long surface swim to the area where the wall dropped off. Early during the descent one diver had buoyancy control problems, but with the help of the more experienced diver he regained control. By this time it had become apparent that the inexperienced divers were overweighted and were having difficulty using their BCs. As they passed their planned depth range, they were dropping like stones and control was slipping away from all three novice divers. At approximately 130 feet, the situation became completely out of control. The novice divers were still dropping while swimming against negative buoyancy rather than using their BCs. Confusion took over in the near-zero visibility. One diver tried to help another by holding on to him and inflating his own BC, but lost his grip and rocketed to the surface with an overinflated BC. Not one of the divers ditched his weight belt.
The toll of the disaster: the two least experienced divers continued descending. One was never found and the other's body was later recovered from near 300 feet. The most experienced diver surfaced and was treated in a recompression chamber. The remaining diver also surfaced only to die of an air embolism.
The Analysis Although no legal actions came of this tragedy, an investigation revealed many human errors and ways in which the deaths could have been prevented. Clearly these divers were diving beyond their personal limits, diving with unfamiliar equipment, diving too deep for their training and experience, diving in demanding and unknown conditions, and not using good judgment. Even the experienced diver was diving beyond his limits by taking inexperienced divers into a situation beyond his ability to control or to give assistance.
Lessons For Life
- Be properly trained for diving, and if you are away from diving for an extended period of time, take a refresher course with the gear you plan to use and under the conditions appropriate to your planned diving. During the refresher course, be sure you are well practiced in buoyancy checks, buoyancy control, emergency ascents, weight ditching and self-rescue.
- Know your dive equipment. The more of your gear that you own and use the better.
- Know your dive site or go with someone who does.
- Only dive in conditions for which you have training and experience or go with a dive pro in shallow, controlled conditions to get to know the territory.
- Limit your depth to your level of experience; dive where there is a bottom within this limit.
- Dive with adequate thermal protection. In water below 55F, a dry suit should be used, which requires additional training.