victorzamora
Contributor
This is an attempt at splitting an OT conversation from another thread, I apologize if I do a bad job 
. The discussion started wandering and ended up at this topic. If you're a rec diver, with OW or AOW or even Rescue training, but no deco training, what do you do when your computer starts yelling at you? How does deco work? What can you salvage?
In simple terms, incurring a deco obligation means that your computer thinks that you'll probably get bent if you go straight to the surface. Many computers, especially "rec" computers, will add a safety stop time to your deco obligation. What this does is it gives you a "Virtual ceiling," which is a term many have heard before. This means you had might as well have rock above you, because you CAN'T go above that depth (statistically, according to your computer's model) without getting bent. Remember, always better bent than dead....but with a little care you can easily reduce your chances of getting bent, as well.
First off, let me say you shouldn't be meaning to go into deco. This should be something that either happens because you weren't paying attention or because you had extenuating circumstances. Do not go into deco without appropriate training, equipment, and planning.
No computer is truly a "rec-only" computer...they'll all track you into deco. Also, all of your dives are technically "deco" dives as you're decompressing on ALL of them. So, if your computer goes into deco it doesn't mean it's given up on you. It'll track your loading until it's all gone, which is usually 18-24 hours, depending on algorithm. An algorithm is simply the method by which it "tracks" your nitrogen loading. Algorithms are exact, but they don't exactly predict real life. They're our best guess on how to keep the bends statistically out of our lives. If you DO go into deco, most computers will give you a ceiling. Do not exceed that ceiling. Go shallower as soon as you can, but ascend slowly. Hang out as shallow as you can. Your most aggressive off-gassing occurs at the ceiling, but that is dangerous as you're pushing your limits AND you might get dragged to the surface easier. Try to hang out at a safe depth slightly below the ceiling. Most computers will give you a ceiling at 10ft before anything else happens. In that case, I like to hang at 20ft or maybe 15ft if the water is calm. Watch the timer drop until it says you're safe to surface. At that point, you can go on up. A question was asked in the other thread about extending your dive, so ascending but not to a deco stop. While this is possible, you've already pushed your luck by going into deco. Wait out your deco, wait for your computer to clear, extend your safety stop, and then get back on the boat. An important thing to note is that ascending the last 10-20ft from your safety stop is the most crucial to take slowly. Ascend so that it takes a couple minutes to surface. Then, rest. Relax. Excercise is likely to get you bent. You might even want to sit at the surface a while (5-10min) if it's an option. See if somebody can get your gear on the boat for you. If you see/feel any symptoms, inquire about O2 on the surface, NOT under water. If I were you, I'd call it for the rest of the day.
I'd like to hear from experienced divers, what you think of my synopsis. Should I have changed something? From rec-only divers, what do you think? Do you have any questions?
I think there's a lot of merit to this, but I'd like to stress that this is ONLY if you mess up and accidentally incur deco....nobody should be doing this without proper training.
. The discussion started wandering and ended up at this topic. If you're a rec diver, with OW or AOW or even Rescue training, but no deco training, what do you do when your computer starts yelling at you? How does deco work? What can you salvage?In simple terms, incurring a deco obligation means that your computer thinks that you'll probably get bent if you go straight to the surface. Many computers, especially "rec" computers, will add a safety stop time to your deco obligation. What this does is it gives you a "Virtual ceiling," which is a term many have heard before. This means you had might as well have rock above you, because you CAN'T go above that depth (statistically, according to your computer's model) without getting bent. Remember, always better bent than dead....but with a little care you can easily reduce your chances of getting bent, as well.
First off, let me say you shouldn't be meaning to go into deco. This should be something that either happens because you weren't paying attention or because you had extenuating circumstances. Do not go into deco without appropriate training, equipment, and planning.
No computer is truly a "rec-only" computer...they'll all track you into deco. Also, all of your dives are technically "deco" dives as you're decompressing on ALL of them. So, if your computer goes into deco it doesn't mean it's given up on you. It'll track your loading until it's all gone, which is usually 18-24 hours, depending on algorithm. An algorithm is simply the method by which it "tracks" your nitrogen loading. Algorithms are exact, but they don't exactly predict real life. They're our best guess on how to keep the bends statistically out of our lives. If you DO go into deco, most computers will give you a ceiling. Do not exceed that ceiling. Go shallower as soon as you can, but ascend slowly. Hang out as shallow as you can. Your most aggressive off-gassing occurs at the ceiling, but that is dangerous as you're pushing your limits AND you might get dragged to the surface easier. Try to hang out at a safe depth slightly below the ceiling. Most computers will give you a ceiling at 10ft before anything else happens. In that case, I like to hang at 20ft or maybe 15ft if the water is calm. Watch the timer drop until it says you're safe to surface. At that point, you can go on up. A question was asked in the other thread about extending your dive, so ascending but not to a deco stop. While this is possible, you've already pushed your luck by going into deco. Wait out your deco, wait for your computer to clear, extend your safety stop, and then get back on the boat. An important thing to note is that ascending the last 10-20ft from your safety stop is the most crucial to take slowly. Ascend so that it takes a couple minutes to surface. Then, rest. Relax. Excercise is likely to get you bent. You might even want to sit at the surface a while (5-10min) if it's an option. See if somebody can get your gear on the boat for you. If you see/feel any symptoms, inquire about O2 on the surface, NOT under water. If I were you, I'd call it for the rest of the day.
I'd like to hear from experienced divers, what you think of my synopsis. Should I have changed something? From rec-only divers, what do you think? Do you have any questions?
I think there's a lot of merit to this, but I'd like to stress that this is ONLY if you mess up and accidentally incur deco....nobody should be doing this without proper training.
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