ren_0373:
I've heard nothing of it being a Dive Master class. The planned depth was 200'. It's been a very "eye opening" experience to read what everybody has to say--good and bad. Thank you.
Yeah, to add a little more on the dive plan:
At about 100 feet down on air (or oxygen/nitrogen mixture) the nitrogen starts becoming noticably narcotic. Short term memory loss can occur and divers will start checking and rechecking their gauges constantly. At 150 feet down on air divers will generally be noticably impaired and will probably feel 'high' like being stoned or drunk. At 200+ it starts to become incapacitating. The effects of nitrogen under pressure are biochemically just like nitrous oxide like at the dentists office or in whip cream canisters. If you want to simulate what its like down there, taking a bunch of nitrous oxide and then trying to function would precisely simulate it without needing to get wet. Most agencies these days teach using helium in breathing gas at depths like 200 feet, which reduces the narcosis. The general rule of thumb is to keep the level of narcosis at the level which is normally experienced at 100 feet on air.
So, they were crawling around on the bottom of puget sound under 200 feet of water, high out of their minds.
The fact that it was a single Al80 tank they were using is also crazy. Typically for 200 foot dives double-100s or double-80s start getting a bit small and most technical divers start to opt for double-130s at those depths (260 cu ft of gas total). They'll also usually carry another one or two 40 cu ft bottles of deco gas, but basically they should have had around 4x the gas they were taking down there. At that depth the gas in their tank would have likely only lasted around 15-20 minutes total. That doesn't give them much time to sort out whatever is wrong and still be able to surface. Normally a tech diver would be carrying about an hours worth of gas at that depth, and would have a much clearer head.
Not only that, but nobody involved in any of this was trained to dive technically, and the recreational limits which are taught by all the agencies are only to 130 feet of depth. There aren't any scuba police to prevent anyone from breaking those limits without getting additional training, but its taught that its not a smart thing to do for good reason....
Its like trying to hike up Everest in the same gear you backpack around the Cascades with...
And someone who apparently should have known better (not Chad I'm talking about) thought all this was a good idea.