Decompression limits and long safety stops

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Ahmedben

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Hello, I am new here, so I am not sure if it is the write place to post this question.
My question is today I had two dives with a new location and the dive center crew seems not paying attention to planing. First dive was 30 minutes and maximum depth was 36m. We have done a safety stop at 3 meters for 4 minutes as my diving computer showed. Second dive was 57 minutes and maximum depth of 33 meters. Dive computer shows 8 minutes safety stop which I have done. And after I finished the 8 minutes. It showed me to have another 3 minutes which I done as well.
My question was the second dive is wrongly planned also after doing these 11 minutes decompression safety stop should fix any risk we accumulate. And should I be safe after these safety stops even though the plan was wrong.
Thanks in advance
 

tursiops

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It appears you were in deco on your second dive, and that the 8 minutes stop was not an optional safety stop but rather a mandatory deco stop. Were you on air or Nitrox? Which computer? How long was your surface interval?
 

boulderjohn

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My question is today I had two dives with a new location and the dive center crew seems not paying attention to planing.
As others have said, you appeared to go into deco on your second dive and had a mandatory decompression stop. It is hard to be sure because we do not have enough information on your dives. They were clearly multilevel dives, or else you would have been in deco on the first dive as well.

I quoted part of your post above because it is really not totally the fault of the dive center's crew. It is your dive and your computer. It is important that you understand and monitor what your computer is telling you. If you are in danger of going into deco and do not want to do that, you need to adjust your dive accordingly. You should have ascended to shallower depths, probably on both dives, to stay out of deco. The divemaster cannot force you to stay too deep when you know you should be getting shallower.
 
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Ahmedben

Ahmedben

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It appears you were in deco on your second dive, and that the 8 minutes stop was not an optional safety stop but rather a mandatory deco stop. Were you on air or Nitrox? Which computer? How long was your surface interval?
Hi, thanks for your replay, surface time before the second dive was 1 hour and 50 minutes. And I have a basic diving computer, Cressida Leonardo and it was air not nitrox
 

tursiops

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Hi, thanks for your replay, surface time before the second dive was 1 hour and 50 minutes. And I have a basic diving computer, Cressida Leonardo and it was air not nitrox
Were the dive profiles "square," that is, most of the time spent at depth, or were you just touching the deepest depth and then ascending shallower for the rest of the dive?
 
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Ahmedben

Ahmedben

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Were the dive profiles "square," that is, most of the time spent at depth, or were you just touching the deepest depth and then ascending shallower for the rest of the dive?
Second dive was mostly at depth
 

tursiops

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Second dive was mostly at depth
Even if it were a first dive -- that is, no residual nitrogen from an earlier dive -- then 57 minutes to 33m, on air is NOT an NDL dive, but rather a deco dive. The PADI tables would only allow 14 minutes to 35m, 20 minutes to 30m. Even the old US Navy tables would only allow 20 minutes at 33m.

As a second dive of the day, you would get even less time at depth.

You were very much into deco, and your computer would have told you that.

You may need to do some refresher work on dive profiles and the use of your computer.

And you need to take responsibility for your own dives and mistakes.
 
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Ahmedben

Ahmedben

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Even if it were a first dive -- that is, no residual nitrogen from an earlier dive -- then 57 minutes to 33m, on air is NOT an NDL dive, but rather a deco dive. The PADI tables would only allow 14 minutes to 35m, 20 minutes to 30m. Even the old US Navy tables would only allow 20 minutes at 33m.

As a second dive of the day, you would get even less time at depth.

You were very much into deco, and your computer would have told you that.

You may need to do some refresher work on dive profiles and the use of your computer.

And you need to take responsibility for your own dives and mistakes.
Yes, lesson learnt, and I do need to refresh my knowledge specially after couple of months away. Normally we dive with more caution centers, and the plan dives but it is my responsibility after all. Tnx for the feed back.
Last question, does the deco. Stop eliminate any DCS risk ?
 

tursiops

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Yes, lesson learnt, and I do need to refresh my knowledge specially after couple of months away. Normally we dive with more caution centers, and the plan dives but it is my responsibility after all. Tnx for the feed back.
Last question, does the deco. Stop eliminate any DCS risk ?
Nothing eliminates DCS risk, but following your computer is a best practice to minimize the risk.
NOT doing deco dives will minimize the risk even more.
 
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