One dead, one missing (since found), 300 foot dive - Lake Michigan

[chillyinCanada]

Did I read that potentially they had "descended too fast"?!

 

[wgw04024]

Submitted to me by the Medical Examiner’s Office on July 9-2019

RICHARD T. BENNETT·TUESDAY, JULY 9, 2019

The information below was submitted to me by the Medical Examiner’s Office on July 9-2019 and was excised of personal names and officials involved for the regard of those involved.
It is submitted for insight or comment only in the hope we never visit this scenario again.

Richard Bennett PADI MSDT #12 rtbennett12@gmail.com

DESCRIPTION OF INCIDENT June 28, 2019, Two deep-water divers perished in diving event.

Report the death of a female believed to be (Not Available), who had been involved in a diving accident 23 to 25 miles out on Lake Michigan. The victim had apparently been diving to a depth of 300 feet.

The Coast Guard had received a distress call at 1323 hours and a Coast Guard Crew went to the site and

retrieved the female from a charter boat and transported her to the Coast Guard Station.

The Coast Guard docked at 1437 hours. They placed the victim on their cot and connected her to a LUCAS device, a mechanical CPR tool. She was intubated and an IO was begun in her left upper arm. A oral gastric tube was inserted and she received a liter of warm fluid, in addition to two doses of Epinepherine. Her core temp was 88.4 and her glucose was 214. She remained in asystole and after approximately one half hour more of CPR her death was pronounced at 1516 hours by Med Base MD #0102, Dr. Ashley Pavlik.

The paramedic stated that the reason the ground unit was dispatched is because the helicopter was on another call. The Flight For Life ground unit had plenty of time to get to the Coast Guard Station because the trip in from the Lake's diving spot was one hour or more away. They reported that the call was for possible decompression sickness and their initial intent was to transport the patient to St. Luke's for hyperbaric treatment. They reported to have no difficulties ventilating her and noted no crepitus during CPR. They felt her lungs were inflating well.

The Harbor Patrol Officers on the scene advised me that the water temperature at 300 feet would be between 35 and 40 degrees. The temperature of the water decreases every 3 feet or so. There are not currents at that depth, and the lake was fairly calm today. The victim and three other divers were out diving on an old shipwreck that sank in 1899 in Lake Michigan. The name of the ship is the L.R. Doty, which was a wooden three-mast Bulk Freighter. The ship is located in approximately 330 feet of water. The site of the dive was approximately 25 miles East of Grant Park or Park Avenue in South Milwaukee, which is considered part of South Milwaukee. The coordinates were 4255.494N and 9872.715W.

The divers were diving off of (Not Available), with is 32 foot Inland Seas Steel Clipper, with a group from the (Not Available) Charter, owned by (Not Available). The diving organization is located at (Not Available) Harbor IL., 60096.

The dive today apparently consisted of four divers and a captain of the boat. The captain remains in the boat while the others dive.

The Captain : He had taken four technical divers out to the Shipwreck, which was located by coordinates. The trip from the Milwaukee Dock out to the shipwreck takes over an hour. When he arrived he tied off on the wreck by throwing over rope and then dragging it until it captures something on the ship. This was done so the divers can follow the rope down to the wreck, and follow it back up.

At 1238 hours the (Female), and her husband, dove down to the wreck. At 1252 the second team of divers descended. The divers descend with four tanks, two of which are bail out tanks. They were using Trimix gas, which is a mixture of Oxygen, Nitrogen, and Helium. The gases are adjusted by the diver, and this is an extremely technical act. At the depth of 300 feet there is a short window of oxygen. The dive is 70-80 minutes total, with 10 to 18 minutes allowed at the bottom. The rest of the time is ascending and requires multiple stops. A stop is required every 10-20 feet, in order to decompress.

SYNOPSIS

This 53-year-old female who is a skilled and certified technical diver had gone on a shipwreck dive to 300 feet using Trimix gas.

She surfaced and was unresponsive. Her husband, who was her diving partner, has not been found. ( Found, read further) It is unclear what went wrong, and her diving equipment and dive computer were lost in the lake, in an attempt to save her life.

At 1323 hours the Captain of the Charter boat heard a splash. He noted (female) floating face up and she was unresponsive. He used a line with a flotation ball to pull her in towards the boat and then used a hook to get her to the rear of the boat. He had to unfasten her gear in order to get her into the boat and the gear floated for a second or so and then sank. The Captain loosened and cut some of the (Females) diving suit so he could connect her to his AED unit, which advised " no shock". He called a mayday out at 1323 hours.

The captain noted her lips were blue and there was a small bit of blood from her nose, which he reported was not uncommon. He had also removed a neck protector during his resuscitation attempts. When the (Female) surfaced she had all of her gear including her underwater scooter robot, four tanks, and her diving computer.

Scooter robots are used to help propel the diver in the water, but also can make the dive more stressful. It is possible the couple descended too fast, but this is unknown. A scooter robot can increase the range underwater for a diver, but also has to be incorporated into gas regulation by the diver.

 

[wgw04024]

A Coast Guard helicopter stationed out of Waukegan, IL was dispatched, as well as Coast Guard Boat from Milwaukee. The helicopter, arrived shortly before the Coast Guard boat, which and arrived at the charter boat at 1403 hours. A Coast Guard member had jumped out of the helicopter, swam to the boat and began CPR. The (female) was then loaded onto the Coast Guard Boat and transferred to the Coast Guard Station arriving at 1450 hours where they were met by the crew from Flight For Life. It is believed that the (Female) had actually made it to the bottom of the wreck as there was silt noted on her flippers.

The Captain of the Charter boat then began banging on the hull of the ship, at 1550 hours when he realized the(Male) (Females husband) was missing. This signals other divers to ascend as fast as safety allows because there is an emergency. The sound from the banging on the hull of the ship can easily be transmitted 300 feet down through the water. The other two divers were interviewed by Detective and they never saw the couple during their dive. It is not known why the (Female’s husband did not surface and she did. He is presumed to be deceased.

Detective also interviewed the family after they were notified.

Both the(Female and Male) have been diving for years. They are both certified Technical Divers and certified in the use of Trimix gas and rebreathers. The couple had planned to dive on the L.R. Doty on Friday. Their plan was to then drive home to Illinois and return on Saturday, 6-29-19, for another dive on The Alice E. Wilds shipwreck.

Detective stated that all the interviews done were consistent stories. To charter a dive the divers have to bring their own equipment and prove they are certified to do a technical dive and have all other certifications. Normally, thousands of dollars are invested in all the diving gear required to do a technical dive.

The detective is attempting to arrange for a Remote Submersion Vehicle on Monday to assist in locating the (husband). Detective stated that there are only 12 to 15 people in the State certified for this type of diving and only six have the capability to search for possible equipment at the bottom of the lake. It is unknown if the (Females) diving equipment and computer can ever be retrieved.

This case was discussed with Dr. (Not Available) and x-rays were ordered. No admission blood was drawn.

SCENE VISIT

The (Female) was located inside of the Flight For Life Med Unit. She was supine on their stretcher. She was cool to the touch. Her hands appeared to be a clonic/tonic state. Rigor was slightly perceived. Lividity was not noted because of her dry suit. She had multiple patterned type of superficial abrasions on her chest from the LUCAS device. Abrasions were also noted to her arms and upper chest from an unknown etiology, but could have come from her dry suit or other diving equipment. She was intubated and had on oral gastric tube in place. An IO was noted to her upper left shoulder. The (Female) was dressed in a dry suit, which had been partially cut away by the paramedics.

The charter boat was being held at the site out on the lake, so I was not able to see it. A CD of photos was requested.

Detective was later able to speak to the Captain of the charter boat and the other divers. An inspection of the boat was done by the US Coast Guard and someone from the DNR. The charter boat was the released. The (Females) diving equipment was not on the boat. Detective took the (Females) cell phone and he has photos of their diving and Trimix certifications. The couple was both certified in Trimix gas and rebreather masks.

Spoke to Detective who stated the divers had no plans to enter inside of the shipwreck.

SYNOPSIS on Male Diver

This 53-year-old male, who is a skilled and certified technical diver, had gone on a shipwreck dive to 300 feet using Trimix gas. He

was found 316 feet down in the water. His wife had surfaced and died on the day of the dive. It is unclear what went wrong.

DESCRIPTION OF INCIDENT

On 7-1-19 @ 1400 hours Detective from the Milwaukee County Sheriff called to report that they had recovered (Male diver), 1-13-1966, from the Lake and he would be at the Coast Guard Station in 30 minutes. (Male) had been missing since 6-28-19 after a diving accident in which his wife, (Above), had also died.

Today the DNR Warden, Milwaukee Harbor Patrol, Sgt., and a private consultant, and Sheriff & detective went to the site of where the shipwreck dive had occurred and using System 3900 digital Side Scan Sonar were able to locate (Male). He was found on the bottom of the lake at 1150 hours in 316 feet of water and 225 feet North of the shipwreck. When the body was located, a search and recovery specialist, used an underwater remote operating vehicle (ROV) with an arm. Using a hook with a rope attached to it they were able to latch on to some piece of the diving gear and manually pulled him up onto the Game Warden's boat. He was removed from the water at 1310 hours. (Male) was found at coordinates 4255.563 N & 0872.7172 W.

 

[RainPilot]

Did I read that potentially they had "descended too fast"?!

Descending too fast can be an issue on CCR, your PPO2 can rise faster than you burn off oxygen.

 

[chillyinCanada]

Thanks for the explanation.

 

[uwxplorer]

Descending too fast can be an issue on CCR, your PPO2 can rise faster than you burn off oxygen.

As usual, the devil is in the details...
Descending compresses the lungs, which the divers need to compensate for (in order not to suffer from lung collapse - i.e. suffocate) by addition of diluent (generally done by the automatic diluent valve or ADV). That will drop the fO2, especially for low fO2 diluent as used by these divers (maybe 10% O2?), and thus, the pO2 (at constant depth/pressure).
In parallel, of course, the divers go down so the pressure increases, and for a given fO2, the pO2 will increase. But read above... The final state depends on a lot of things, including diver lung volume versus counterlung volume, etc.
Then there is O2 consumption and addition.
O2 metabolism is about constant without over exertion, so that contributes a little to the drop, but not enormously. Overexert, and the picture might change (as argued in a previous exchange).
O2 addition is zero in an electronic unit (as the rEvo should have been configured for a dive at those depth), until the divers reach final depth and set their unit to high setpoint (typically pO2 = 1-1.4, depending on diver preference). On a manual/hybrid unit, where O2 flows continuously at a constant rate (about sufficient to sustain metabolism at rest), this addition will contribute a bit to the fO2/pO2 equation, but, once the max depth for constant mass flow is reached, this is essentially shut off. And then trouble starts to happen.

 

[Kay Dee]

Any data available as to how long the wife had been down for before being found on the surface, i.e. total elapsed dive time?

As to fast descents 'causing problems' as it were on CCR, I have (unintentionaly) pushed my po2 up well above 1.6 while descending on a scooter before I noticed / corrected it (on a Mk 15.5). And on dives less than the 100m being discussed here.

 

[Marie13]

Any data available as to how long the wife had been down for before being found on the surface, i.e. total elapsed dive time?

As to fast descents 'causing problems' as it were on CCR, I have (unintentionaly) pushed my po2 up well above 1.6 while descending on a scooter before I noticed / corrected it (on a Mk 15.5).

The above quoted ME’s report has it.. The Winns descended at 1228 and the captain noticed her on the surface at 1323 when he head a splash. So 55 min.

 

[Marie13]

I was on Double Action’s Hammond, IN (Chicago) boat yesterday. Recreational charter, two wrecks 40-50ft. There was a guy with a RB. Not sure of model. Looked to be a lot of electronics. Anyway, I was in the cabin when he was filling out waiver and showing certs to crew. He was being asked to show RB certs. Not sure if this is new or not.

 

[Dan]

The above quoted ME’s report has it.. The Winns descended at 1228 and the captain noticed her on the surface at 1323 when he head a splash. So 55 min.

55 min = going to 300’ and back, but how fast is the descent rate?

Took 12 min for Ahmed Gabr, World record holder with OC, to reach 332.5m. That’s 27.7m/min or 90.9 ft/min, but it took him nearly 15 hours to get back to the surface.

CCR would need a gas blending time and feedback time from gas analyzer to O2 solenoid if I venture to guess. What would be an acceptable descent rate on CCR?