We have been diving in Blue Hole in Egypt last week. We did 80 meter trimix dive with the following gazes: bottom - trimix 12/54, travel - Nitrox 32 and deco - Nitrox 80. Bottom time was 11 min. The dive was planned on Z Planner and we all have VR 3 with us. After 12 meter stop our instructor unexpectedly ascended and went to the surface. He made two deep stops and 15 and 12 meters 1 minute stops. He switched for Nitrox 32 on 24 meters. In total 25 minutes of deco have been missed.
The guy was approached with oxygen for approximately 3 hrs. After surface interval of 7 hours we went back thru passages with altitude change of 600 meters. When we were passing mountain the victim breathed oxygen. Next day he got no symptoms but small itching in finger tips.
Has anybody heard similar stories and its results? I personally think that the guy is simply lucky that he didn't get to the Chamber.
:doctor:
MikeFerrara
November 13th, 2003, 06:45 AM
I'm more interested in why he went to the surface than why he didn't get bent.
Even at that depth the bottom time was short and the required decompression not a lot. Depending on the ascent speed deep and how much time was spent in the descent, I'm not really surprised that he didn't get bent.
I am surprised that the instructor couldn't hold his stops though.
Magus
November 13th, 2003, 07:33 AM
that was not just an Instructor. It is IANTD instructor-trainer.
The official story that he got sleep on deco stop. Drop his second stage out of the mouth and breath with salt water and as the result went to the surface.... sounds strange...but you never know
O-ring
November 13th, 2003, 09:05 AM
<points at the agency>
<points at the selection of gasses>
<points at the VR3s>
<doesn't think more pointing is required>
;)
:hiding:
Magus
November 13th, 2003, 09:18 AM
2 O-ring:
not sure that got your comments fully...:hmmm:
O-ring
November 13th, 2003, 09:19 AM
Magus once bubbled...
2 O-ring:
not sure that got your comments fully...:hmmm:
LOL...I was just playing around. There are other accounts of people that "should" have gotten bent that didn't though...if I can find some I will shoot you the links.
MikeFerrara
November 13th, 2003, 09:42 AM
O-ring once bubbled...
<points at the agency>
<points at the selection of gasses>
<points at the VR3s>
<doesn't think more pointing is required>
;)
:hiding:
LOL
80% doesn't put you to sleep.
If those gasses and a VR3 let you skip deco all together I'm gonna get me a VR3 and switch to 80%.
O-ring
November 13th, 2003, 09:44 AM
MikeFerrara once bubbled...
LOL
80% doesn't put you to sleep.
If those gasses and a VR3 let you skip deco all together I'm gonna get me a VR3 and switch to 80%.
Actually that's a damn fine point...sure sounds like it gets me out of the water quick!
Big-t-2538
November 13th, 2003, 09:47 AM
O-ring once bubbled...
Actually that's a damn fine point...sure sounds like it gets me out of the water quick! You can get out real quick if you inflate your dry-suit and drop some lead at depth...
Genesis
November 13th, 2003, 03:40 PM
That sounds pretty fizzy to me.
I ran that profile on VPM-B (conservatism +2) and I would be expecting an iron pony ride if I blew it off at the point he did.
O-ring
November 13th, 2003, 03:41 PM
LOL..
Genesis
November 13th, 2003, 03:55 PM
doesn't take much off the runtime - only three minutes total.
A bit of extra conservatism is good for a laugh?
O-ring
November 13th, 2003, 03:58 PM
Genesis once bubbled...
doesn't take much off the runtime - only three minutes total.
A bit of extra conservatism is good for a laugh?
Dude, stop it...you're killing me..
100days-a-year
November 13th, 2003, 04:44 PM
O-ring ,did you eat chocolate today?;)Gen,I think he might have been teasing about B being already conservative as compared to A.I ran some MPLANs last night for giggles and got the same times out as VPMB on 0,just didn't have the deep stops.Sometimes even the blind squirrel will find an acorn,it's called luck.
Genesis
November 13th, 2003, 05:10 PM
I'm a "B" fan, even though I know I can turn it back into "A".
It hasn't bent me yet, and I feel good when I get out of the water - that's usually a good enough endorsement for something that can't be "exact" like deco, no? :)
VPM (set to "original") has a 46 minute runtime on that profile.
VPM (set to "B"), nominal, has a 45 minute runtime.
Looks pretty identical to me for this profile.
(I'm running 3.22)
100days-a-year
November 14th, 2003, 05:37 PM
10-4 on the endorsement.No DCS ,no headache,out sooner than a computer=just fine.
Genesis
November 14th, 2003, 07:04 PM
I've found that my Vytec clears me before my VPM deco plans do!
Which kinda puts the lie to the idea that the Vytec is so awful-conservative, eh? :)
O-ring
November 14th, 2003, 07:21 PM
How does it compare to a VPM profile with conservatism set to nominal?
Genesis
November 14th, 2003, 09:35 PM
Oops - I screwed up something - just realized I had the deco gasses wrong (50/50 instead of EANx80).
EAN32 for travel (which I ignored, since you'd switch off it presumably as soon as you are normoxic on the backgas) and EAN32 and EAN80 for the deco.
Nominal produces a 43 minute runtime.
+2 produces a 45 minute runtime.
So its a whole 2 minutes (not 3) more deco for the "+2" setting on that profile.
Switch to Nitrox 32 at 120', switch to EAN80 @ 30' for both.
+2 produces an extra stop at 80' for one minute (otherwise the first stop after the switch at 120 is at 70') and adds one minute on the 30' stop.
The profiles are otherwise identical.
Here 'ya go:
V-Planner 3.22 by R. Hemingway, VPM code by Erik C. Baker.
Decompression model: VPM-B
DIVE PLAN
Surface interval = 2 day 0 hr 0 min.
Altitude = 0ft
Conservatism = + 2
Dec to 200ft (4) on Trimix 12.0/54.0, 50ft/min descent.
Dec to 250ft (4) on Trimix 12.0/54.0, 60ft/min descent.
Level 250ft 6:10 (11) on Trimix 12.0/54.0, 1.03 ppO2, 89ft EAD
Asc to 160ft (14) on Trimix 12.0/54.0, -30ft/min ascent.
Stop at 140ft 2:00 (16) on Trimix 12.0/54.0, 0.63 ppO2, 41ft EAD
Stop at 120ft 2:00 (18) on Nitrox 32.0, 1.48 ppO2, 99ft EAD
Stop at 80ft 1:00 (20) on Nitrox 32.0, 1.09 ppO2, 64ft EAD
Stop at 70ft 1:00 (21) on Nitrox 32.0, 1.00 ppO2, 56ft EAD
Stop at 60ft 2:00 (23) on Nitrox 32.0, 0.90 ppO2, 47ft EAD
Stop at 50ft 2:00 (25) on Nitrox 32.0, 0.80 ppO2, 38ft EAD
Stop at 40ft 3:00 (28) on Nitrox 32.0, 0.71 ppO2, 30ft EAD
Stop at 30ft 4:00 (32) on Nitrox 80.0, 1.53 ppO2, 0ft EAD
Stop at 20ft 13:00 (45) on Nitrox 80.0, 1.28 ppO2, 0ft EAD
Asc to sfc. (45) on Nitrox 80.0, -30ft/min ascent.
Off gassing starts at 184.4 ft
OTU's this dive: 49
CNS Total: 19.0%
84.6 cu ft Trimix 12.0/54.0
17.6 cu ft Nitrox 32.0
14.4 cu ft Nitrox 80.0
116.5 cu ft TOTAL
V-Planner 3.22 by R. Hemingway, VPM code by Erik C. Baker.
Decompression model: VPM-B
DIVE PLAN
Surface interval = 2 day 0 hr 0 min.
Altitude = 0ft
Conservatism = Nominal
Dec to 200ft (4) on Trimix 12.0/54.0, 50ft/min descent.
Dec to 250ft (4) on Trimix 12.0/54.0, 60ft/min descent.
Level 250ft 6:10 (11) on Trimix 12.0/54.0, 1.03 ppO2, 89ft EAD
Asc to 160ft (14) on Trimix 12.0/54.0, -30ft/min ascent.
Stop at 140ft 2:00 (16) on Trimix 12.0/54.0, 0.63 ppO2, 41ft EAD
Stop at 120ft 2:00 (18) on Nitrox 32.0, 1.48 ppO2, 99ft EAD
Stop at 70ft 1:40 (21) on Nitrox 32.0, 1.00 ppO2, 56ft EAD
Stop at 60ft 1:00 (22) on Nitrox 32.0, 0.90 ppO2, 47ft EAD
Stop at 50ft 2:00 (24) on Nitrox 32.0, 0.80 ppO2, 38ft EAD
Stop at 40ft 3:00 (27) on Nitrox 32.0, 0.71 ppO2, 30ft EAD
Stop at 30ft 3:00 (30) on Nitrox 80.0, 1.53 ppO2, 0ft EAD
Stop at 20ft 13:00 (43) on Nitrox 80.0, 1.28 ppO2, 0ft EAD
Asc to sfc. (43) on Nitrox 80.0, -30ft/min ascent.
Off gassing starts at 184.4 ft
OTU's this dive: 46
CNS Total: 17.8%
84.6 cu ft Trimix 12.0/54.0
16.0 cu ft Nitrox 32.0
13.4 cu ft Nitrox 80.0
114 cu ft TOTAL
(I set "last stop" to 20' since we are nearly always diving in open ocean and a 10' stop can be a pain in the butt if there is any kind of wave action at all. 20' is much more comfortable. I also have deep stops enabled, minimum stop times of 1 minute a 2 minute minimum stop time on all gas switches and oxygen window effect used.)
100days-a-year
November 15th, 2003, 04:16 PM
Genesis,is that with a square profile on the bottom and what depths?Spearfishing,I usually meander within 10' of max or more and even greater variances on wrecks.Deeper diving will probly exacerbate the differences closer to NDLs as the Vytec credits ascent and descent.'Course I run 0 conservatism on B.I've seen you post the profiles you dove ,any 100' to 130' dives?My Oceanic is approaching old age and if I can NDL as long and get some accel-deco credit when I wear a bunch of gas I'd be happy to replace it.
Bob3
November 15th, 2003, 06:39 PM
Not sure why the guy in question blew off the stops, but "standard protocol" for a skipped stop is to return the diver to the depth of the missed stop & continue from there, and extend the stops above 40' by 1.5x.
Genesis
November 15th, 2003, 08:44 PM
Genesis,is that with a square profile on the bottom and what depths?Spearfishing,I usually meander within 10' of max or more and even greater variances on wrecks.
More or less square profiles, yes. Spearfishing some of the time, video some of the time, just screwing around some of the time.
All depths over 100' - below that I usually get bored before I hit the NDL, as I custom mix my Nitrox for "best mix" and get a looong dive out of it above 100'. At 130-140 I'm into deco pretty quickly.
