Partial Pressure of 2.0 ?!

[ajduplessis]

Shearwaters (most likely other vendors) will allow you to increase to PO2 limit/parameters and will recalculate the required deco based your shape coming out. However the associated risks by increasing the PO2 and the time you "save" off the deco obligation is seriously disjointed. Adding a lot of risk to shorten your deco by 3-5 min is not very clever.

In the end, "if you do the crime (non-NDL) you have to to the time (deco)!!" There are not many shortcuts when it comes to deco. You have 3 choices: Stick to industry standards, become a "deco pioneer" and change the way the industry look at things, or become part of the incident stats.

 

[kwinter]

There has been a certification course developed by IANTD for in water recompression. IWR would be the only instance that a pO2 that high would be used. It should involve being on a FFM and having a buddy to monitor you. I think a gas switch block to be able to take air breaks would be useful too. There was a recent thread on TDS about the IWR course.
http://thedecostop.com/forums/showt...-the-IANTD-In-Water-Recompression-program-yet



Please pardon any typos. Sent from my iPhone using Tapatalk

 

[sammyseadog]

I get what you're saying Tortuga68. The tables we are using are pretty thouroughly tried and tested on "guinea pigs" already, but I'm just trying to get some data to help rewrite them. Its not for a computer model, but applied to a particular industry that I just want as safe as possible. Unfortunately my only way is to dive them and see for myself, but want a computer that will track me and keep at least a bit of a check on me.
There will be a number of divers all together with the same profiles and oxygen will be given with air breaks as per previous studies and dives that have been proven to work numerous times.

I've written to Shearwater, Liquivision and VR Technologies to see what they say about their computer's abilities to monitor these variables combined with a 3metre/minute ascent rate (industry standard!!) and will see what they come back with. I have noted that liquivison's XEO can be programmed up to 2.0 PPO2 and you can even put in an alarm for a 1m/min ascent rate, which is promising.

Not sure about what what you say though victorzamora, about being locked out of Liquivisons if you break protocols. We will not dive below 10msw on 100% O2, 9 metre staged, do you think that would prevent lock out?

Cheers again

 

[Tortuga68]

I'm not sure what victor means either, my Liquivision X1 has never 'locked' me out even when I have left it set on air while doing accelrated deco (and therefore getting out of the water way ahead of the schedule it wanted me to follow).

As far as wanting your industry to be "as safe as possible", to me that would mean sticking to a PP02 of 1.6 for deco. Not that you couldn't increase that but I just don't see the benefit from what information you have provided.

Can you share some other details? I'm curious to know what your typical max depth, bottom gas, bottom time, surface interval, repetitive dive series etc are.

 

[victorzamora]

It was my understanding that Liquivisions will lock you out if you do something stupid. I can't remember what the example was, but omitted deco and exceeding MOD are what I recall causing the lockouts.

SammySeaDog, I meant that the computer goes into "violation" mode and refuses to continue tracking your progress in any way.

 

[JohnN]

ALSO, if you have ever been in a chamber ( I have as a tech!), you'll know that they take people down to 18 metres and give them 100% oxygen, that's 2.8 partial right?!

Your susceptibility to OxTox is greater when wet than dry. To the best of my knowledge, the mechanism is not completely understood but is related to the Mammalian dive reflex. Yes a USN Table 6 schedule is 100% O2 @ 60' (60 minutes with air breaks) but if someone seizes in a chamber it may be uncomfortable and messy but not necessarily life threatening

 

[Nuribromanski]

hope u will be the one diving this way, and not some other poor sob

 

[rongoodman]

It was my understanding that Liquivisions will lock you out if you do something stupid. I can't remember what the example was, but omitted deco and exceeding MOD are what I recall causing the lockouts.

I've never heard of a circumstance under which a Liquivision or Shearwater computer would lock you out.

 

[jcaplins]

The Liquivision X1 has a note in the manual: "There are no lock out or "use tables" errors of any kind in V-planner Live"

Also, You can select either 1.6 or 1.9 in the "PP02 stops" setting. From the manual:

"This allows the diver to set the ppO2 at which the alarm triggers for the final stop when using 100% O2 as deco mix. the selections are ppO2 of 1.6 or 1.9. this option is intended only for those performing O2 stops at 9m / 30ft."

 

[sammyseadog]

I'm not going into details as I want to keep my job!! These are tried and tested dive profiles with hundreds of dives on numerous divers.

I'm trying to get some data to adjust the profiles a bit towards Nitrox and 6 metre Deco stops. I'm not the guy in charge though. Thats why I need data from one of these

I am looking at the Liquivision XEO and the Shearwater Petrel Standalone and just wondered if anyone has any preferences for any reason? Build quality or reliability, battery length, readability, ease of use...etc. Just wondering about the "tap" nature of the liquivision, but like that you can set an alarm for the 3 metre ascent rate.
Also I need to be able to get graphs and printouts of dive profiles that show everything related to O2 exposure and N2 saturation.

Anyone know much about what info you can get from these post-dive?

Any info appreciated! Cheers for everything so far!