1 danger of icing of the scuba regulator – a neglected risk while diving in mountain lakes daniel...
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Danger of icing of the scuba regulator– a neglected risk while diving in mountain lakes
Daniel Hothorn (sport student) and Hans-Volkhart Ulmer (Physiologist)
Institute of sports science, Johannes Gutenberg-Universität, Mainz, Germany, [email protected]
4th international Symposium: “High altitude influence on human performance: science and praxis” – Bohinjska Bela (Slovenia)
Sept. 8-13, 2009
___________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
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Diving in mountain lakes is very attractive.Some special risks are described in literature, however:
Especially the problem of decompression during ascent of divers under changed pressure conditions as consequence of the lower ambient pressure in hight, relevant for diving in mountain lakes > 300 m
Introduction, aim, methods, results, discussion, final conclusions
___________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
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Introduction, aim, methods, results, discussion, final conclusions
________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
An other problem is described rarely:The icing of the scuba regulator by
water temperatures < 10 °C.
The scuba regulator reduces the pressure of the air bottles from 200 bar in two steps until actual ambient pressure for respiration under water
Technical instructions: e.g. http://www.divers-travel-guide.com/fileadmin/bilder/pdf/HandbuchS
L21.pdf
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Introduction, aim, methods, results, discussion, final conclusions
________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
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Introduction, aim, methods, results, discussion, final conclusions
______________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Icing of the scuba regulator
caused by - lower water temperatures (permanent temperatures of 4 - 10 C° in depths > 20 m)- the Joule-Thomson-effect (decompression of gases in a pressure reducer effects cold)
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Diving in mountain lakes is only marginally included in the basic courses of the great diving associations PADI and SSI, and only referring to the modified decom-pression conditions during ascent.
A similar situation was found in nearly all other special courses for diving in mountain lakes.
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Prevention against fatal accidents by icing:
Complete redundant system of scuba regulatorsand knowledge, how to switch it in case of icing of the primary system, also in darkness
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Introduction, aim, methods, results, discussion, final conclusions
HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Diving equipment with two bottles for com-pressed air and redun-dant scuba regulators
ANLINKER, U. & CISCATO, W.: TDI Trimix. 1. Auflage, TDI Germany, 2007, Jüchen www.tdisdi.de
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Switching on the 2nd scuba regulator without look contact (REINTS, 2009)
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
By literature and own experience it seemed for us that the danger of icing of the scuba regulator and the necessity of a redundant scuba regulator is not sufficiently known among divers
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Introduction, aim, methods, results, discussion, final conclusions
_____________________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Aim
– Evaluate knowledge about the icing problem– Evaluate use of correct equipment against scuba regulator icing– Evaluate the risk of accidents by icing of scuba the regulator
In context with divers at a typical mountain lake (Walchensee, Germany, 802 m)
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Introduction, aim, methods, results, discussion, final conclusions
______________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Methods
– Inquiry with a special manual of 30 divers at the Walchensee (802 m)
– Interview with 3 regional therapeutic recompression centres
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Introduction, aim, methods, results, discussion, final conclusions
_____________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Results
Inquiry of the divers:
- Most of them knew the necessity of special decompression procedures
- but only half of them knew the danger of icing of the scuba regulator and used, in consequence,
a complete redundant regulator system
- Only a minority had passed a special course for diving in mountain lakes
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Introduction, aim, methods, results, discussion, final conclusions
_____________________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Interview with decompression centres:
Nearly all serious accidents of divers in mountain lakes were caused by iced scuba regulators
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Discussion
This study underlines the often neglected importance of icing of scuba regulators during diving in mountain lakes (definition > 300 m).
- Neglected in the curricula of basic courses- Neglected by divers to join special courses for diving in mountain lakes- Neglected by divers to use redundant regulator systems and to train how to use in case of icing under realistic conditions
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Final conclusion
- In every basic course for divers the risk of icing of the scuba regulator should be underlined, combined with the necessity to join special courses for diving in mountain lakes. - In these special courses the necessity to use redundant regulator systems should be explained and it should be trained during diving in darkness, how to use them in the case of icing of the primary system.
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
Thanks for Copyrights:Wilk reints (sheet 9) www.dir-m.com" H. Dederichs (sheet 8) www.tdisdi.de
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Introduction, aim, methods, results, discussion, final conclusions
__________________________________________________________HOTHORN & ULMER: Risk of icing scuba regulator, 4th Symposium: Altitude & praxis
The end