Wazee Incident

[M&P+4]

The Jackson County Sheriff's Department says two men are dead after a scuba diving accident at the Wazee Lake Recreation Area near Black River Falls Saturday afternoon.
The sheriff's department says they arrived at the recreational area just after noon Saturday to find a 57-year-old male being given CPR by two fellow divers.
Deputies say one diver, a 60-year-old male was also in need of medical treatment, a third 53-year-old male diver was also treated at the scene.
All three men were taken to Black River Memorial Hospital where the 57-year-old was pronounced dead.
Deputies say the other two patients were airlifted to Hennepin County Medical Center where the 60-year-old male died just before 8:00 Saturday evening. The 53-year-old is still being treated at the Hennepin County Medical Center
The official cause of death of the two men is pending autopsy results.
The Jackson County Sheriffs Department is still investigating the incident.
The sheriffs department says the Wazee Lake Recreation Area is a popular scuba diving destination that is used by many divers in the Midwest area. The lake has depths of approximately 350 feet with very clear water for diving enthusiasts.

[DeepDiverBob]

any more details on this accident?

[M&P+4]

here are a few news links -

http://www.weau.com/news/headlines/98181934.html

http://www.startribune.com/local/south/98201404.html?elr=KArksLckD8EQDUoaEyqyP4O:DW3ckUiD 3aPc:_Yyc:aUac8HEaDiaMDCinchO7DU

http://wcco.com/local/scuba.divers.minnesota.2.1798950.html

In reading them it sounds like a couple of them were looking to hit 200 feet and the third stayed around 140, something went wrong and all three of them acended too fast. The third diver has been released from the hospital.

[theskull]

Among other things, another case of people diving beyond their training and abilities.

Anyone can do deep deco dives when everything goes according to plan. It's when things go wrong that being prepared, practiced, and coached can make the difference between a problem and a fatality. Or, as in this case, multiple fatalities.

theskull

[b1gcountry]

I didn't read all the links. Were these guys not trained for decompression?

[M&P+4]

I didn't read all the links. Were these guys not trained for decompression?

I'm not sure of their level of training. Keith K. from Wazee Sports is quoted several times stating they were only certified to 150 feet.

Here's the latest link with a newscast that interviews the survivor. He surfaced early and skipped a mandatory 60 deco stop, it sounds like he was low on air.

http://www.weau.com/news/headlines/98292014.html

http://kstp.com/news/stories/S1648772.shtml?cat=1

[scububa]

From what I read...
seems they were diving to 200 on air
seems that one of them was previously treated for similar DCS issues

[b1gcountry]

There's always going to be a bigger number. I don't get it.

[M&P+4]

From what I read...
seems they were diving to 200 on air
seems that one of them was previously treated for similar DCS issues

I had heard a 200 foot dive on air also - but in reading some of the other stories and listening to the guy that survived they did dive with 'mixed gas', what ever that may imply.

Not being nitrox certified (so far I haven't had the need or desire) or a deep diver, I do have a question about diving that deep on air. I know that narcosis effects most certainly increase at depth, but at some point/depth is there a risk of oxygen toxicity with straight air? My assumption is that it does and that is one of the reasons for the tri-mix concotion but I'm not 100% sure.

[scububa]

You are right on both accounts. Trimix helps to increase the trade space between narcosis, Oxtox and decompression durations.

Without getting into teaching on line, I wouldn't go below 180 on air and that would be an ideal condition dive plan. More usually 160 leaving a buffer. Depending on dive complexity, environment and conditions, the recommended depth limits get shallower.

Helium increases decompression durations. Depth and decompression requirments require carrying more gas. Also, logistical planning is more complex and at deeper depths, consideration for possible too little oxygen at the surface has to be factored.

And, before you put too much stock in my comments, I haven't finished my Trimix just yet.

[theskull]

You are right on both accounts. Trimix helps to increase the trade space between narcosis, Oxtox and decompression durations.

Without getting into teaching on line, I wouldn't go below 180 on air and that would be an ideal condition dive plan. More usually 160 leaving a buffer. Depending on dive complexity, environment and conditions, the recommended depth limits get shallower.

Helium increases decompression durations. Depth and decompression requirments require carrying more gas. Also, logistical planning is more complex and at deeper depths, consideration for possible too little oxygen at the surface has to be factored.

And, before you put too much stock in my comments, I haven't finished my Trimix just yet.

All 'buba's comments are right on the money.

M&P -- Nitrox is also referred to as mixed gas. And a dive to that depth would have much easier deco requirements if the deco was done on EAN 50 starting at 70 ft., Oxygen at 20 ft., or both. The report is that their bottom gas was air. That is a concern, but the much bigger concern is that they did not have the training to conduct dives to this depth. There is a very big difference between a dive to 150 and a dive to 200. Deco obligations climb exponentially, as do the consequences of not meeting those obligations!

theskull

[vtach67]

The biggest (and most obvious) reason to dive trimix at those depths is narcosis. The next best reason (but rarely considered) is the density of air at those depths. The density of air at those depths creates significant reduction in both regulator performance and the ability for the human body to exchange oxygen and CO2. Any respiratory rate beyond a normally active respiratory rate can lead to CO2 retention, which leads to agitation, increased respiratory rate, tachycardia, etc... Basically, when everything is going fine there are no issues. When things go sour and you cannot psychologically manage the narcosis, you get the "fight or flight" dump of epinephrine...hyperventilate, tachycardia, etc...that starts the downward spiral. The fitness level of the diver would obviously have a factor here also.

I guess we don't really know for sure what happened but there sure are some flags pointing in the "preventable tragedy" direction...

[BLU DIVER]

There is absolutely NO substitution for diving safe! You shouldn't "just" incorporate safety, live it...it's a core value. I have always like NAUI's "Saftey through education." As we all know small challenges can balloon and spiral out of control very fast underwater. I can't help but think they knew the risk and consequences for their actions. TheSkull nailed it, another example of people diving beyond their training and abilities. Being prepared, practiced, and coached can make the difference between a problem and a fatality.

[M&P+4]

The next best reason (but rarely considered) is the density of air at those depths. The density of air at those depths creates significant reduction in both regulator performance and the ability for the human body to exchange oxygen and CO2. Any respiratory rate beyond a normally active respiratory rate can lead to CO2 retention, which leads to agitation, increased respiratory rate, tachycardia, etc...

I had never heard the air density issue - something new for me to chew on for a while. Is this something that a rebreather addresses also?

[vtach67]

Definitely "work of breathing" and CO2 are big concerns to rebreather divers. I wouldn't say that the rebreather itself addresses those issues as much as a properly trained rebreather diver does. Selecting the proper diluent mix is more focused towards pO2 management. In planning for depths exceeding the recreational range you will need to drop your oxygen percentage and to do that you need an inert gas like helium. That also provides additional benefits like reduced narcosis and gas density.

[b1gcountry]

I had never heard the air density issue - something new for me to chew on for a while. Is this something that a rebreather addresses also?

I've noticed rebreather divers are more apt to run higher % He mixes in their diluent, but it's the Helium, not the rebreather that helps with the density. A good rebreather has a higher work of breathing than a good regulator though, so I would say that a rebreather actually hurts you as far as WOB goes.

I've never dove a RB in my life, btw.

[BLU DIVER]

I've noticed rebreather divers are more apt to run higher % He mixes in their diluent, but it's the Helium, not the rebreather that helps with the density. A good rebreather has a higher work of breathing than a good regulator though, so I would say that a rebreather actually hurts you as far as WOB goes.

I've never dove a RB in my life, btw.

You didn't try a RB at Mermet with Greg Such over the winter?

It was a little different, I recall having to exhale through my nose, so I could inhale. There was like a gas traffic jam taking place...:) I wouldn't mind doing it again.

[b1gcountry]

Nope. It's like premarital sex...no trying a rebreather or scooter until I'm ready to commit.

Tom

[scububa]

I call it "Jim's first rule of motorcycles."

"Never ride a motorcycle bigger than what you own!"

It results in trips to the motorcycle shop and the bank.

[skdvr]

I call it "Jim's first rule of motorcycles."

"Never ride a motorcycle bigger than what you own!"

It results in trips to the motorcycle shop and the bank.

I know the feeling...

After riding the Harley it just reached up and grabed my wallet.

Phil