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Posted : September 9, 2008
Hi Had A Test Paper For My Ocean Diver Exam And I Am Stuck On One Question Please Can You Help ?
What Should You Never Do Just Before Making A Breath Heald Dive
A; Take Vigorous Exercise
B; Rest
D; Take Several Deep Breaths Close Together
E; Blow Your Nose
Posted : September 10, 2008
Not sure the idea of using a forum Q&A is to pass exams !!!

Research and re-read materials... however in the spirit of good form and my obligation to answer valid Q's...

A... not recommended as this stimulates the cardiovascula system will build up CO2 levels in the lung (which is the real stimulus to breathe) and would elevate the need for the body to have O2... on breathe hold dives - being calm, relaxed and miminalist in the need for O2 and expunged of CO2 are key... if you pick A your wrong.

B. good answer - but check the context of the question it says 'do just before' - i take the grammar to mean immediately before ... so this too is wrong

C. can't fault you on this choice - don't you just love those who set exams and precis too much the question :-)

D is the correct answer as this will achieve what I said above and seriously reduce CO2 levels in the lungs as this will expunge the dead air spaces (we tend to use about a third to a half of our lung volume during normal things) - these spaces become rich in CO2 (the stimulus to breathe) - these deep breathes also inspire and hence infuse rich supplies of O2 for the body to use during the breathe hold phase.

E. maybe of some use, but not really a sensible choice.

The choice of several deep breathes for breathe holding dives is key - too much and the levels of O2 will fall dangerously low before CO2 levels reach a high enough level to be a burning desire to breathe... take several to be no more than three. Low O2 (Hypoxia) is not a stimuls to breathe, but high CO2 (Hypacapnia) is !!!

There in lies a very dangerous but interesting way we are built...

Duck diving where you hold your breathe is relatively safe and fun way to see the underwater world.. build up your techniques so that you may enjoy this even more.

regards Andrew.
Answer provided by ADM Diving

Andrew Dawson-Maddocks
Additional Comment

Posted : September 10, 2008 by - lindag7770
thanks for your help, please dont feel too guilty for helping me as the test paper is not my actual exam just a runthrough of how it is set up and what to expect......i could never ask otherwisw lol
again thanks
Additional Comment

Posted : September 12, 2008 by - ADM Diving
No problem at all - more than happy to help on these Q's and any other relating to diving.

Cheers Andrew.
The views expressed by the author are their own and the publishers accept no liability for the advice and views expressed by the author, or other users, which are provided as a general service to divers. Users are warned that secondary posts are the views of other users and may not be technically correct.
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