Controlled emergency swimming ascent

Controlled Emergency Swimming Ascent (CESA) (aka "blow and go") is a technique used by scuba divers as a safety measure when a diver has run out of breathing gas in shallow water and must return to the surface.^[1]

The technique involves simply ascending at a controlled pace, while exhaling slowly or vocalizing a continuous sound. As the diver ascends, the pressure in the lungs increases relative to surrounding water pressure. Exhaling serves to equalize this difference. Hence, the diver can continue exhaling throughout the ascent, and still have air in their lungs at the surface. For the same reason, if the diver fails to exhale during the ascent, lung over expansion injury is likely to occur. As the diver swims to the surface (making the ahhhhh sound) they will feel as if they are not running out of breath; this is because the compressed air they inhaled at depth is expanding as they ascend.

References

1. ^ Samson RL, Miller JW (eds.) (1979). "Emergency Ascent Training.". 15th Undersea and Hyperbaric Medical Society Workshop. UHMS Publication Number 32WS(EAT)10-31-79. http://archive.rubicon-foundation.org/4260. Retrieved 2008-08-07. 

Additional reading

• Walker, D (1978). "Emergency Ascents: some background information.". South Pacific Underwater Medicine Society Journal 8 (2). ISSN 0813-1988. OCLC 16986801. http://archive.rubicon-foundation.org/6175. Retrieved 2008-08-07. 
• Knight, J (1978). "Free Ascent Training.". South Pacific Underwater Medicine Society Journal 8 (2). ISSN 0813-1988. OCLC 16986801. http://archive.rubicon-foundation.org/6180. Retrieved 2008-08-07. 
• Egstrom, GH (1978). "Ascents.". South Pacific Underwater Medicine Society Journal 8 (2). ISSN 0813-1988. OCLC 16986801. http://archive.rubicon-foundation.org/6181. Retrieved 2008-08-07. 
• Curtis, ASG (1978). "Free Ascents: A view from the Scottish Sub-Aqua Club.". South Pacific Underwater Medicine Society Journal 8 (2). ISSN 0813-1988. OCLC 16986801. http://archive.rubicon-foundation.org/6179. Retrieved 2008-08-07. 
• Graver, DK (1978). "In support of emergency ascent training.". South Pacific Underwater Medicine Society Journal 8 (3). ISSN 0813-1988. OCLC 16986801. http://archive.rubicon-foundation.org/6186. Retrieved 2008-08-07. 

This diving-related article is a stub. You can help Wikipedia by expanding it.v · Categories: Underwater diving Underwater diving stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем решить контрольную работу Drug prohibition law Controlled Ground Water Area Look at other dictionaries: Controlled Emergency Swimming Ascent — CESA: Controlled Emergency Swimming Ascent is a technique used by scuba divers as a safety measure when a diver has run out of breathing gas in shallow water and must return to the surface. [cite journal |author=Samson RL, Miller JW (eds.) |title …   Wikipedia CESA — Controlled Emergency Swimming Ascent (Governmental » Military) *** Compañía Española de Sistemas Aeronáuticos (International » Spanish) Centre For Elective Surgery At The Alfred (International » Australian) …   Abbreviations dictionary Glossary of SCUBA diving — Here is a glossary of scuba diving terms: Contents 1 A F 2 G L 3 M R 4 S Z A F Altitude Diving  diving at a locat …   Wikipedia Ascend — means to go up, fly, or soar.Ascend (ascendant, ascendance, ascendancy/ascendency, ascended, ascender, ascending, ascent, ascension, etc) may also refer to:Anatomy/Medicine * Ascending aorta * Ascending cervical artery * Ascending colon *… …   Wikipedia Notaufstieg (Tauchen) — Der Notaufstieg ist ein aus einer Notsituation heraus resultierender, schneller und direkter Aufstieg bis zur Wasseroberfläche. Dabei werden eventuell die empfohlenen Aufstiegsgeschwindigkeiten und Dekompressionsstopps missachtet. Ein Notaufstieg …   Deutsch Wikipedia Scuba set — A scuba diver in usual sport diving gear A scuba set is an independent breathing set that provides a scuba diver with the breathing gas necessary to breathe underwater during scuba diving. It is much used for sport diving and some sorts of work… …   Wikipedia Rebreather — A fully closed circuit electronic rebreather (Ambient Pressure Diving Inspiration) Acronym CCUBA (Closed Circuit Underwater Breathing Apparatus); CCR (Closed circuit rebreather), SCR (Semi closed rebreather) Uses Breathing set …   Wikipedia Scuba diving — Not to be confused with Self contained breathing apparatus, which describes breathing sets used out of water. Scuba diver Scuba diving ( SCUBA originally being an acronym for self contained underwater breathing apparatus, now widely considered a… …   Wikipedia Germany — /jerr meuh nee/, n. a republic in central Europe: after World War II divided into four zones, British, French, U.S., and Soviet, and in 1949 into East Germany and West Germany; East and West Germany were reunited in 1990. 84,068,216; 137,852 sq.… …   Universalium literature — /lit euhr euh cheuhr, choor , li treuh /, n. 1. writings in which expression and form, in connection with ideas of permanent and universal interest, are characteristic or essential features, as poetry, novels, history, biography, and essays. 2.… …   Universalium 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”