Posted by fred on January 09, 2001 at 21:31:04:
In Reply to: Re: Scuba Diver Dies Off Mission Beach posted by fred on January 08, 2001 at 22:10:42:
Questions remain after two deaths during dives
http://www.signonsandiego.com/news/metro/20010109-9999_1m9divers.html
By Terry Rodgers
UNION-TRIBUNE STAFF WRITER
January 9, 2001
Both died about a week apart while diving the same waters known as Wreck Alley two miles off Mission Beach.
And experts say both made critical mistakes.
Yet exactly what led to their deaths may never be known because both had become separated from their diving partners and were alone when the end came.
Mia Tegner, 53, who died Sunday, was a renowned Scripps Institution of Oceanography marine biologist with 27 years of experience as a scuba diver. Monica Vila, who died Dec. 29, was a 41-year-old recreational diver with fewer than 20 dives.
Scuba experts said yesterday they can imagine how a novice such as Vila, who was unfamiliar with cold-water diving, might panic after getting separated from her diving partners. It's harder for colleagues to imagine what went awry for Tegner, a veteran of more than 4,000 dives.
"All of us (in the diving community) are shocked. We're in disbelief. How could it happen to Mia?" said Dick Long, an expert diver and president of the San Diego Oceans Foundation.
Diving fatalities here are unusual during winter because it's the season when the more hard-core divers are in the water, Long said. Fatalities are far more common in the spring, he said, "when people dig out that dusty diving gear they haven't used in a long time."
The Divers Alert Network recorded 83 deaths of American divers worldwide and foreign and American divers using U.S. waters in 1998, the latest year statistics were available.
Equipment failures are extremely rare and 1 percent or less of the victims die from decompression sickness, a network spokeswoman said.
Comparing the two recent diving deaths is difficult because there are few clues, said Lifeguard Lt. Brant Bass, chairman of the Diving Death Investigation Committee for the County Medical Examiner.
Vila died during her descent toward the Yukon, a 366-foot-long Canadian destroyer escort ship that has become an international diving attraction since it was scuttled here in July. Wreck Alley includes the Ruby E, a 165-foot-long Coast Guard cutter; the El Rey, a kelp cutter; a Navy Electronics Lab research tower; and the roadway and pilings of the old Ingraham Street bridges, which were replaced in 1985.
Vila was last seen in 60 feet of water. Her body was found at the ocean floor 100 feet down. She drowned despite a nearly full tank of air.
Two of her actions in the water are considered inadvisable: She was with two dive "buddies" rather than with a single partner and she failed to surface when she became separated from her companions, experts said.
It's not unusual for divers to get separated from their partners, Bass said.
The procedure is to wait a minute, conduct a quick search then surface before continuing the dive, he said.
Tegner was ascending from an 85-foot dive when her air apparently ran out, forcing her to surface before she could complete her final decompression stop, city lifeguards said.
Tegner surfaced and disregarded a suggestion from a companion that she stay aboard the craft. She grabbed another air tank and returned to the water to complete her so-called safety stop -- a pause for three to five minutes in 15 to 25 feet of water, Bass said.
The safety stop has been done routinely by divers for 15 years to provide an extra margin of safety by clearing away any remaining nitrogen bubbles from a diver's blood.
The air tank Tegner had grabbed later bobbed to the surface. Her body was found on the ocean floor.
Divers are taught to stay on the surface and head immediately to a hyperbaric chamber if they make a mistake during their ascent.
"Going back down after having missed a decompression stop is considered the more dangerous thing to do," Bass said.
Also, in Tegner's case, there was a breakdown of the buddy system.
Wayne Pawelek, diving safety officer at Scripps, said he's mystified by the accident.
"We don't know what caused her to release the tank and fall to the bottom," he said. "We have to put the puzzle together and figure out what happened."