DAN Fires Back at Chamber Operator March 14, 2006
Posted by Andy Carroll in : Decompression, News, Uncategorized , add a commentThis story has been going on for a while now, as DAN have been complaining about the high prices that SSS network charge fo rtheir chamber services. Here is the latest press release;
We deeply regret that many DAN members and others in the diving community were the focus of a broadcast email campaign by the SSS Network. The latest statement from SSS is designed to intimidate and frighten DAN members, and much of the information is untrue, misleading and contradicts previous statements from chambers within the SSS Network. DAN and SSS are in dispute over the excessive treatment charges, which DAN believes are not reasonable and customary in comparison to other hyperbaric chambers and will damage the diving industry long term if not addressed now. By refusing to accept DAN insurance, SSS is attempting to place the burden of payment on the diver in order to gain leverage to force DAN’s insurer to accept higher treatment charges.
Scuba Diving Air and its Effects on Decompression December 25, 2005
Posted by Andy Carroll in : Decompression , add a commentFirstly, an intro into what happens when we go scuba diving underwater. As you know air is made up of 20.9% or .209 Oxygen and 79.1% or .791 nitrogen there or thereabouts. As we go deeper these numbers or partial pressures increase. So at 10 mtrs or 2 bar its .418 and 1.582 (we show these as Po2 and PN2) as it is multiplied by 2. Scuba diving to 30 mtrs we multiply by 4 bar which is .836 Po2 and 3.16 pN2, you can see how the nitrogen part is growing quite quickly. The oxygen part we don’t really worry about as it is a metaboliser (we do but its not relevant today) and our body uses it in other ways, but the inert gas, the nitrogen, is soaked into our body, we could call it saturation.
You will maybe have heard of fast tissues and slow tissues. We use these terms to describe how quickly the tissue in question is saturated with nitrogen. This is determined largely by bloodflow (perfusion) If a tissue has good bloodflow then it is said to be a fast tissue. The blood itself is a fast tissue, along with the major organs and central nervous system. Slow tissues have poor blood flow such as bones, skin and fat. These classifications are quite important in scuba diving deco as it is how they behave which determines how long we decompress and can effect our scubadive plan.
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Buhlmann, Computers, and Helium and what it means in scuba diving December 16, 2005
Posted by Andy Carroll in : Decompression , 1 comment so farThis is a bit of a geeky article on deco and gasses and scuba diving decompression models. I wrote it a back in July 2004, when I was initially getting into deeper diving using mixed gasses and starting to do scuba dives which required decompression. I thought it might be useful to some people doing the same and I just fancied getting a bit geeky, as you do.
Disclaimer: Like you, I am continually learning about deco and technical diving. These posts are written primarily to ensure that I have understood what I have learnt and hopefully to encourage others to explore this fascinating subject. I do not guarantee this is correct and I do not recommend you do anything without knowing why you are doing it. I am not responsible if you read anything I write and change your plans and get bent. I am not responsible if your buddy or anyone you know gets bent, and I am not responsible should your dog be run over by a car or because you find a fingernail in your Big Mac. You make your own choices.
Just wanted to make that clear.
What I am discussing today is the decompression model that most scuba diving computers are based on and why we, as technical divers, are beginning to question these models.
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