OP
- Messages
- 333
- Reaction score
- 132
- # of dives
- 500 - 999
Bent. I guess it really can happen to me.
- Thread starter TechDeep
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
I have to be with Jim on this one. Sometimes Jim is a bit harsh in his assessments, but here he explains the outcome very succinctly. I dive with a computer, but I do my dive planning with tables for this reason. As I noted recently on another thread, I also plan conservatively due to age (60) and other facors. I do find it a bit scaqry that some agencies (including mine, PADI) certify divers who have never worked with dive tables. Hopefully they will dive with me or someone like me, who uses them. Actually, I am a big "wheel" guy too, though you can plan repetitive and multilevel dives with either. So Divemaster TechDeep, perhaps you should do a little remediation on the tables so you don't repeat this mistake. Just a thought.
DivemasterDennis
DivemasterDennis
I bothered to read the manual and legal stuff they've posted.
"THE LYNX DIVE COMPUTER AND T1 TRANSMITTERS ARE INTENDED TO BE ONLY A SECONDARY SOURCE OF DECOMPRESSION AND TANK PRESSURE INFORMATION, TO BE USED IN CONJUNCTION WITH ANOTHER (PRIMARY) SOURCE OF TANK PRESSURE AND ANOTHER (PRIMARY) DECOMPRESSION PLANNING TOOL. THE LYNX DIVE COMPUTER AND T1 TRANSMITTERS CAN STOP FUNCTIONING OR PROVIDE INACCURATE INFORMATION, WITHOUT WARNING, DUE TO VARIOUS FACTORS (INCLUDING DEFECTS OR SOFTWARE BUGS)."
"THE DECOMPRESSION SOFTWARE INCLUDED WITH THE LYNX DIVE COMPUTER IS BASED UPON THE BÜHLMANN DECOMPRESSION ALGORITHM, WITH OPTIONAL GRADIENT FACTORS. YOU MUST READ THE APPLICABLE USER MANUAL AND FULLY UNDERSTAND THE BÜHLMANN DECOMPRESSION ALGORITHM AND GRADIENT FACTORS BEFORE YOU SET UP YOUR LYNX DIVE COMPUTER OR USE IT FOR THE FIRST TIME. USE OF THE LYNX DIVE COMPUTER AND T1 TRANSMITTERS DOES NOT GUARANTEE THAT YOU WILL NOT SUFFER DECOMPRESSION SICKNESS OR DEATH."
4.1 Mode (Rec/Tec/Gauge)
This menu item allows you to select between Rec, Tec or Gauge mode of operation. The default setting is "Rec Mode", and the default gas is "Air".
Rec Mode
"In Rec mode, the LYNX functions as a one-gas computer. The default mix is Air. You can set any mix from 21%-40% oxygen, including common mixes such as Air (21%), 32% nitrox or 36% nitrox.
The Liquivision Recreational Diving Model in Rec Mode has been carefully tuned to maximize bottom time on both the first dive of the day and on repetitive dives while maintaining diver safety.
DCS risk is carefully managed and in the same ranges as most popular dive tables in use today. Gradient factors control the overall no decompression time and reduction factors are applied during surface intervals to increase safety.
In this mode, the LYNX’s primary function is to provide you with your No Decompression Limit (NDL), i.e., the amount of time you can spend diving without incurring any decompression. If you complete your dive within the NDL period, the LYNX will prompt you to complete a Safety Stop for 3 minutes at 5m / 15ft. If, at any time during these 3 minutes, you drop below 6.5m / 21ft, the safety stop counter will turn off and reset. It will begin again once you return to the safety stop depth of 5m / 15ft."
"Tec Mode uses the same basic model. Preset gradient factors control the overall decompression calculations but no reduction factors are applied during the surface interval. Using Tec Mode for repetitive recreational diving will yield more aggressive NDL’s after short surface intervals reducing dive safety. Divers should use the mode best suited for their intended dives.
In this mode the LYNX assumes you are planning to incur some decompression obligation and gives you control over a number of extra settings, such as your level of Conservatism, your Dive PO2 and Deco PO2 levels, and the depth of your Last Deco Stop (please see the relevant sections of the Dive Setup menu for mode information)."
4.2.1. Conservatism
Your LYNX calculates No Decompression Limits (NDLs) or your decompression times based on the proven Bühlmann ZH-L16C1 algorithm. This menu item allows you to add conservatism to the LYNX decompression calculations using three pre-set levels:
Level "0" - standard Bühlmann ZH-L16C with no added conservatism (Gradient Factors 100/100)
Level "1" - Bühlmann ZH-L16C with some added conservatism (Gradient Factors 30/85)
Level "2" - Bühlmann ZH-L16C with more added conservatism (Gradient Factors 30/75) "
------
In summary, you should never use this computer as a principle method of planning a dive. You should know everything there is to know about diving ZHL16-C+GF even though we do not disclose what GF the computer is using. Interesting. To your credit, you can't know what GF it's using in Rec mode and you can't change it. 30/70 is gaining a bit of traction in some circles. I would be curious to see, barring PFO, or other clinical pre-disposing factors if you felt better using 30/75. Again, you should probably grab the relevant training, warning, warning, disclaimer, disclaimer.
Last edited:
Nirvana
Contributor
Multilevel diving must be planned with a good deal with of caution if using the RDP. This paper deals exactly with this issue. The authors explain that utilizing the RDP to plan multilevel dives can lead to excessive nitrogen loading in the slowest compartments. They go on to describe an adequate method of planning multilevel dives with the RDP and what level of extra conservatism is necessary.
Well Stated!
One of the things that I have noticed since using a heart rate monitor is my heart rate will increase significantly as I leave the weightless world and have to deal with gravity. My heart rate will go from around 60 to around 120.
Isn't this period of time when your most likely to get bent?
deborahdelamar
Contributor
I can only speak from my experience. Every case I've worked has been different -- as were the individuals suffering from the disease.
Unless we're dealing with an AGE from a documented rapid ascent or a coronary event or other unusual circumstance, determining an individual cause runs from difficult to impossible. We work hard to compile as complete a picture as possible -- before, during and after (the latest series of) dive(s). And we usually end up with a number of things that, in combination, probably caused the DCS.
Exertion after immersion is something that we ask about. Researchers in the field recommend that it be avoided, along with many other things... However, in our real world, divers need to board boats after diving -- or haul heavy gear or repair flat tires. It's important for divers to know that exertion may play a role so they may avoid hard work and stress after diving.
It has been pointed out to me that I may have been a bit harsh in my earlier reply. And to a point I see where that is true. But to explain my mindset a bit, I had just finished teaching an SDI wreck class with limited penetration at a popular training site in my area. During the weekend we were there and I was drilling into my student's head to plan, plan, plan, and plan again and never trust a computer, Divemaster, or Instructor to keep you safe, we saw repeated things that sent chills up my spine. In addition to the wreck training he got a good lesson in how easy it would be for someone to put themselves in a position to get hurt and have no idea that they were doing it.
The worst part was when the people pulling these stunts were obviously, from the way they were interracting with what were clearly new OW students, "dive professionals". So when a dive pro posts about what I specifically warm my students not to do - flying the computer - on top of what I just witnessed, it has the tendency to remove some of the tact filtering software in my brain.
I stand behind what I said 100%. No apologies for that. What I do apologize for is the way it was said and the "deserved hit" remark. That was out of line.
The worst part was when the people pulling these stunts were obviously, from the way they were interracting with what were clearly new OW students, "dive professionals". So when a dive pro posts about what I specifically warm my students not to do - flying the computer - on top of what I just witnessed, it has the tendency to remove some of the tact filtering software in my brain.
I stand behind what I said 100%. No apologies for that. What I do apologize for is the way it was said and the "deserved hit" remark. That was out of line.
PfcAJ
Contributor
I think the terms "deserved" and "underserved" in regards to DCS does a disservice to anyone trying to understand tables, computers, algorithms, and DCS in general.
The only way to ensure not getting bent is to not dive. Period. Everything past that is a game of probability. Even if you follow the tables to the letter, you still have a nonzero chance of getting bent. Its the name of the game. It can happen to anyone, and if you dive long enough, its probably going to happen to you.
The only way to ensure not getting bent is to not dive. Period. Everything past that is a game of probability. Even if you follow the tables to the letter, you still have a nonzero chance of getting bent. Its the name of the game. It can happen to anyone, and if you dive long enough, its probably going to happen to you.
I agree, which is why I earlier advocated "explained" and "unexplained."
I got the idea from a couple of past threads in which evidence seemed pretty conclusive to me that the term "deserved" actually hindered proper treatment. Those threads said that many people are reluctant to seek treatment when they get symptoms because they don't want to have to admit that they screwed up. They fear a judgmental attitude from doctors when they seek treatment. Those threads indicated that this often does happen. In the case of a friend of mine who got bent, he did indeed get a stern lecture from the doctor treating him, and the doctor gave him a copy of Bruce Weinke's book on diving at altitude to read while in the chamber so he would know better than to screw up again in the future.
He got bent after three days of diving with me, and we did every dive together. We drove home together after the last dive, going over the same mountain pass that the doctor said was to blame for his DCS. I felt great after that weekend--probably the best I had ever felt after a weekend of decompression diving. So why did I feel great while he "deserved" three days of chamber treatments? I guess it is just "unexplained."
miked
Contributor
As it was explained to me,some 9-10 years ago, "expected/unexpected" and "explained (explainable??)/ unexplained (unexplainable?)", and another pair that escapes me, came into use when dive medicine professionals felt that "deserved/undeserved" had a stigma (of implied blame?) attached to them that may have kept people from seeking medical help, in cases where they thought that they might have DCS.
While I think that the change in terms may be " a bit too politically correct", if it encouraged more divers to seek help, then I'm all for it!
When I had my hit, the Dr. said "you did nothing wrong, broke no dive or safety protocols, but sometimes S**t happens."
That cleared it up nicely!!
While I think that the change in terms may be " a bit too politically correct", if it encouraged more divers to seek help, then I'm all for it!
When I had my hit, the Dr. said "you did nothing wrong, broke no dive or safety protocols, but sometimes S**t happens."
That cleared it up nicely!!
Similar threads
