Missed deco stop, lock out?
- Thread starter scubadada
- 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 seen lots of posts on this. and one that said that shearwater does nto lock out adn that was the sales appeal. I dont think appeal has anything to do with it. The majority of computers are made for rec divers, of which many are new divers. the lock out feature is IMO a safety aspect to force untrained divers in deco to remain on the surface for a day if they mis a deco stop after aquireing an unplanned obligation. Shearwater was not made for the rec diver. It was made for the tech diver who has deco training. A tech guy misses a stop and he knows how to fix it with out carrying a problem into the next dive. Perticularly handy when wearing a computer and doing RD where deco stops are not in line with the computer's plan, but are done in a different fashion.
fsardone
Solo Diver
You are decompressing at 27 or 24 mt and you run out of 30/30 or 35/30 and your next available mix is EAN 50 or Heliox 50/20 which has a mod of 21 would blow the remaining time at 24 (probably one or two minutes) or breathe an too rich mix? Depending on the GF I am set (I dive 45/85) probably blowing a few minutes at 24 is better than breathing a too rich mix.
Just a realistic example ...
OP
- Messages
- 20,473
- Reaction score
- 19,828
- Location
- Philadelphia and Boynton Beach
- # of dives
- 1000 - 2499
fsardone
Solo Diver
You should not but:
you are on the loop and loose it and panicking or for a CO2 hit you use up the deep bailout ... while getting shallower. So now you have only rich deco gas ...
Running scenarios makes you prepared for emergencies ...
These are tenuous examples and way beyond the scope of the thread. If I were using He or on CCR my computer choices would be very different, and frankly the cost of the computers would be "noise" in the overall equipment cost.
Most people who used the argument about a computer locking out if a deco violation is made are trained for Deco anyway on or don't' read the manual.
Most of teh RGBM computers have a clear warning that the computer isn't meant for deco use. They use the words, accidently, inadvertently (or my favourite from Cressi) by negligence) then they will guide you to the surface if you follow them. If you choose to ignore them - well you're sat on the bench.
PADI tables state less than 5 mins deco, then 8 min @ 5m and no diving for 6 hrs or more than 5 mins then no less than 15 mins (air supply permitting ) then no diving for at least 24 hrs
For the most part people who "bend" their computers do so by ignorance and foolish practices
Edit: For the record, I have no issue in people deciding against such computers because they don't meet the need of the type of diving they're involved in or intend to participate in after proper training
I have little sympathy for those who get themselves locked out by engaging in poor or negligent practices
On the Garmin Descent you can disable the deco lockout feature:
Descent Mk1 - Dive Setup
I dive with a Shearwater Perdix as my primary and the Garmin Descent as my backup. The both use Buhlmann with gradient factors.
Descent Mk1 - Dive Setup
I dive with a Shearwater Perdix as my primary and the Garmin Descent as my backup. The both use Buhlmann with gradient factors.
Not only that, but also (to quote Wienke) DCS is a hit or no hit binary statistic, like a coin toss. If you "bend" a computer built on that assumption, it's already "hit". It can't continue computing your "no hit" loading, it has to clear its little mind before it can function as designed again.
The alternative design decision is to keep computing the loadings, with no regard to how far above the M-values they are. I can see how some technical divers in emergency situations may find that useful -- but as a programmer I much prefer code that has well-defined limits and throws EOUTOFRANGE when the luser tries to push it beyond its design specs.
I dont know much about the programming but I am assuming that the lock up is a response to a x level violation. Majopr or minor vilation it does nto care.... It then allows no ability to recover. A tech diver can probably work out a recovery strategy when a rec diver would not be able to. I see this when visualizing RD and computer calculated deco's if teh comuter calls for 3 min at x and 2 min at y and you do it in reverse there may be no foul. In addition if the computer was set up for some rediculous GF settings it would cause it also. I would want the puter to contain a complete record of the dive and not the portion up the a shortened calculated stop.
Similar threads
