Science of underwater diving

The science of underwater diving includes those concepts which are useful for understanding the underwater environment in which diving takes place, and its influence on the diver. It includes aspects of physics, physiology and oceanography. The practice of scientific work while diving is known as Scientific diving.

Physics

Diving Physics are the aspects of physics which directly affect the underwater diver and which explain the effects that divers and their equipment are subject to underwater which differ from the normal human experience out of water.

These effects are mostly consequences of immersion in water, the hydrostatic pressure of depth and the effects of the pressure on breathing gases and buoyancy. Other effects are the physical influences of the underwater environment on humsn sensory perception. An understanding of the physics is useful when considering the physiological effects of diving and the hazards and risks of diving.

Physiology

Physiology of underwater diving is the physiological influences of the underwater environment on the physiology of air-breathing animals, and the adaptations to operating underwater, both during breath-hold dives and while breathing at ambient pressure from a suitable breathing gas supply. It, therefore, includes both the physiology of breath-hold diving in humans and other air-breathing animals, and the range of physiological effects generally limited to human ambient pressure divers either freediving or using underwater breathing apparatus. Several factors influence the diver, including immersion, exposure to the water, the limitations of breath-hold endurance, variations in ambient pressure, the effects of breathing gases at raised ambient pressure, effects caused by the use of breathing apparatus, and sensory impairment. All of these may affect diver performance and safety.[1]

Immersion affects fluid balance, circulation and work of breathing.[2][3] Exposure to cold water can result in the harmful cold shock response,[4][5] the helpful diving reflex and excessive loss of body heat.[6][7][8][9] Breath-hold duration is limited by oxygen reserves, and the risk of hypoxic blackout, which has a high associated risk of drowning.[10][11][12]

Large or sudden changes in ambient pressure have the potential for injury known as barotrauma.[1][13] Breathing under pressure involves several effects. Metabolically inactive gases are absorbed by the tissues and may have narcotic or other undesirable effects, and must be released slowly to avoid the formation of bubbles during decompression.[14] Metabolically active gases have a greater effect in proportion to their concentration, which is proportional to their partial pressure, which for contaminants is increased in proportion to absolute ambient pressure.[1]

Work of breathing is increased by increased density of the breathing gas, artifacts of the breathing apparatus, and hydrostatic pressure variations due to posture in the water. The underwater environment also affects sensory input, which can impact on safety and the ability to function effectively at depth.[2]

Environment

The ocean and aquatic environment is described by oceanography and limnology. These are directly influenced by aspects of geology, weather and climate. The underwater environment is inhabited by organisms of great diversity, some of which may be hazardous to the diver.

See also

  • Science of underwater diving portal

References

  1. 1 2 3 US Navy Diving Manual, 6th revision. United States: US Naval Sea Systems Command. 2006. Retrieved 26 May 2008.
  2. 1 2 Pendergast, D. R.; Lundgren, C. E. G. (1 January 2009). "The underwater environment: cardiopulmonary, thermal, and energetic demands". Journal of Applied Physiology, Vol. 106 no. 1. American Physiological Society. pp. 276–283. doi:10.1152/japplphysiol.90984.2008. ISSN 1522-1601. Retrieved 12 October 2016.
  3. ↑ Kollias, James; Van Derveer, Dena; Dorchak, Karen J.; Greenleaf, John E. (February 1976). "Physiologic responses to water immersion in man: A compendium of research" (PDF). Nasa Technical Memorandum X-3308. Washington, DC: National Aeronautics And Space Administration. Retrieved 12 October 2016.
  4. ↑ Staff. "4 Phases of Cold Water Immersion". Beyond Cold Water Bootcamp. Canadian Safe Boating Council. Retrieved 8 November 2013.
  5. ↑ "Exercise in the Cold: Part II - A physiological trip through cold water exposure". The science of sport. www.sportsscientists.com. 29 January 2008. Archived from the original on 24 May 2010. Retrieved 24 April 2010.
  6. ↑ Lindholm, Peter; Lundgren, Claes EG (1 January 2009). "The physiology and pathophysiology of human breath-hold diving". Journal of Applied Physiology. 106 (1): 284–292. doi:10.1152/japplphysiol.90991.2008. Retrieved 4 April 2015.
  7. ↑ Panneton, W. Michael (2013). "The Mammalian Diving Response: An Enigmatic Reflex to Preserve Life?". Physiology. 28 (5): 284–297. doi:10.1152/physiol.00020.2013. PMC 3768097. PMID 23997188.
  8. ↑ Sterba, J.A. (1990). "Field Management of Accidental Hypothermia during Diving". US Naval Experimental Diving Unit Technical Report. NEDU-1-90. Retrieved 11 June 2008.
  9. ↑ Cheung, S.S.; Montie, D.L.; White, M.D.; Behm, D. (September 2003). "Changes in manual dexterity following short-term hand and forearm immersion in 10 degrees C water". Aviat Space Environ Med. 74 (9): 990–3. PMID 14503680. Retrieved 11 June 2008.
  10. ↑ Pearn, John H.; Franklin, Richard C.; Peden, Amy E. (2015). "Hypoxic Blackout: Diagnosis, Risks, and Prevention" (PDF). International Journal of Aquatic Research and Education. Human Kinetics Inc. 9 (3): 342–347 – via ScholarWorks@BGSU.
  11. ↑ Edmonds, C. (1968). "Shallow Water Blackout". Royal Australian Navy, School of Underwater Medicine. RANSUM-8-68. Retrieved 21 July 2008.
  12. ↑ Lindholm, P.; Pollock, N. W.; Lundgren, C. E. G., eds. (2006). Breath-hold diving. Proceedings of the Undersea and Hyperbaric Medical Society/Divers Alert Network 2006 June 20–21 Workshop. Durham, NC: Divers Alert Network. ISBN 978-1-930536-36-4. Retrieved 21 July 2008.
  13. ↑ Brubakk, A. O.; Neuman, T. S. (2003). Bennett and Elliott's physiology and medicine of diving, 5th Rev ed. United States: Saunders Ltd. p. 800. ISBN 0-7020-2571-2.
  14. ↑ Bauer, Ralph W.; Way, Robert O. (1970). "Relative narcotic potencies of hydrogen, helium, nitrogen, and their mixtures".
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