Mailing List Archive

Mailing List: techdiver

Message Display

Hi Chris,

> I have a question about in water-recompression.  I have read a very good
> article conserning this in aquacorps "not sure on the publish date" but
> it was a good article.  

I'm glad you found the article useful.  It (the one published in aquaqCorps)
was actually an abridged version - a more complete version can be found at: 

http://www.bishop.hawaii.org/bishop/treks/palautz97/iwr.html


> My question is the following: Why is it
> neccesary to use 100% O2 at 30 ft?  I know that it would speed up the
> off gassing but the risk of convulsions in my mind seems too high!  

There is no specific reason why the O2 treatment must "necessarily" be 
conducted at 30 feet.  That just happens to be the way the original 
"Australian" method was published.  Back when it was originally 
published, the rule of thum for maximum O2 exposure was the US Navy's 
"Exceptional Exposure" PO2 limit was 2.0 atm. I imagine that the authors 
of the Australian IWR method (Edmonds et al) considered IWR an 
"Exceptional" situation, and thus went for the therapeutic benefits of 
increased ambient pressure.  Subsequent authors of IWR methods simply 
followd the lead of O2 at 30 feet.

Personally, I would consider that too aggresive in most IWR situations.  
My personal choice would more likely be about 20-25 feet; but it really 
depends on so MANY variables, that it's difficult to generalize.

> I believe that it would be neccesary to have full face mask to do this 

Yes, the Australian method (and subsequent methods) do specify a FFM as 
mandatory equipment (along with an un-bent tender diver on air, etc.).

> but what if I didn't have one?  All-be-it this is a very far fetched
> circumstance, but I would like to know other peoples opinions on the
> matter.  I would also like to know if any of you have done it or
> witnessed it being done.

I've done it.  I've witnessed it being done to others. I've talked to 
many others with first-hand experience.  My impression is that every 
situation is unique, and thus the best solution (in my opinion) is to 
disseminate as much information as possible, which will allow more 
informed decisions and less uninformed speculation to take place in an 
IWR situation.

Hope that helps.

Aloha,
Rich

Richard Pyle
Ichthyology, Bishop Museum                deepreef@bi*.bi*.ha*.or*
1525 Bernice St.                          PH: (808) 848-4115
Honolulu, HI 96817-0916                   FAX: (808) 841-8968
       "The views are those of the sender and not of Bishop Museum"

--
Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]