Hard questions I'm sure ya'll can answer.

[sssteinkamp]

In the context of another discussion, someone asked the following. Since I am quite new to diving, I have no answers and was hoping that ya'll would be smarter than I am.

Thanks!

Shane

***

If you are on EANx24 at 140 ft and I'm making a normal ascent, at what depth
should I switch to 100% O2 and finish my decompression IAW my computer?

Also, If my first decompression stop is at 9 meters, and I switch to EANx50,
my EAD is two meters. I know then that the nitro leaves my body as if I
were only a two meters deep, w/out ascending that shallow.

What I'd like to know is: Would that probably cause DCS?

Oh.... and if I'm planning an accelerated deco dive that has me at 55% "CNS
Clock" time as I leave the 20 foot stop. I have a final 15 ft stop choice
of using O2 for 74 min's, or lower oxygen EANx80, but for a longer 92 min's,
which gas and time should I choose?

 

[BabyDuck]

ok, i don't get it. :33: you said this is someone else's question. are you wanting to get it *answered*, or *explained*? either way, prolly 'basic scuba discussions' isn't the best choice of forum for deco questions. maybe try a more techie area?

 

[DandyDon]

ok, i don't get it. :33: you said this is someone else's question. are you wanting to get it *answered*, or *explained*? either way, prolly 'basic scuba discussions' isn't the best choice of forum for deco questions. maybe try a more techie area?

What she said! But since you're new here, and may not know how to ask - I will ask for you.

Btw, go to Introductions forum and post one if you'd like... :14:

 

[sssteinkamp]

ok, i don't get it. :33: you said this is someone else's question. are you wanting to get it *answered*, or *explained*?

Well, I mostly understand the questions, but I'd like to have the answers.

either way, prolly 'basic scuba discussions' isn't the best choice of forum for deco questions. maybe try a more techie area?

Ah. Sorry to be a noob. Where should I put it then?

Thanks.

Shane

 

[OWSI176288]

Your friends question can best be answered by receiving formal Technical Dive training. While technical (decompression) diving is more hazardous, the additional hazard is reduced and managed through extensive training and practice.

This isn't something you should figure out on you own, on the fly. The margin for error is just too great.

 

[Web Monkey]

If this is someone else's dive, it's their responsibility to plan their own dive.

If this was your dive (that you already did) and you're worried about DCS, call DAN and describe your symptoms, if any.

If this is a dive you're planning, don't do it until you can answer all these questions yourself. There are other dangers besides DCS, including (but not limited to) O2 Toxicity that could easily kill or injure you.

Terry

In the context of another discussion, someone asked the following. Since I am quite new to diving, I have no answers and was hoping that ya'll would be smarter than I am.

Thanks!

Shane

***

If you are on EANx24 at 140 ft and I'm making a normal ascent, at what depth
should I switch to 100% O2 and finish my decompression IAW my computer?

Also, If my first decompression stop is at 9 meters, and I switch to EANx50,
my EAD is two meters. I know then that the nitro leaves my body as if I
were only a two meters deep, w/out ascending that shallow.

What I'd like to know is: Would that probably cause DCS?

Oh.... and if I'm planning an accelerated deco dive that has me at 55% "CNS
Clock" time as I leave the 20 foot stop. I have a final 15 ft stop choice
of using O2 for 74 min's, or lower oxygen EANx80, but for a longer 92 min's,
which gas and time should I choose?

 

[sssteinkamp]

Your friends question can best be answered by receiving formal Technical Dive training. While technical (decompression) diving is more hazardous, the additional hazard is reduced and managed through extensive training and practice.

This isn't something you should figure out on you own, on the fly. The margin for error is just too great.

I appreciate that fully, and this isn't a dive I'm qualified to do currently. I was just hoping someone could help me with the numbers as a theoretical.

Shane

 

[BabyDuck]

Sorry to be a noob.

hey, not at all, and i hope you didn't get the feeling i was putting you down for being new to the boards. definitely not my intent. i'd try asking under 'technical diving specialties'.

edit - never mind, they moved it for ya! i'm sure it can be answered here.

 

[Jason B]

Deco dive training over the internet is not the way to go.
Are you nitrox certified yet? If not start there. If so, then sign up for an advanced nitrox/deco procedures course.

 

[jptrealty]

Here is what I would do, understand this is a relatively shallow dive, I don't see the need to cary 3 gasses??

1) Use 80% O2 for your 30, 20 and 10 (that you should stop at 15' for), take 1/3 of the time off of your 20 and 10 from AIR DECO tables only (if diving air).

2) Use back mounted doubles for your bottom mix.

100% 02 might get you out of the water a LITTLE quicker, but why its not much time we are talking about.

Your 02 clock isn't running at full throtle on 80%, and I think its a little more conservative. The few minutes you will save isn't worth the additional bottle of 50/50.

Does this help??