Deco for divers : a diver's guide to decompression theory and physiology

Fully updated and revised. Award winning__Deco for Divers__provides a comprehensive overview of the principles underlying decompression theory. Mark Powell has written a book that for the first time allows the average diver to fully understand the principles behind this fascinating aspect of diving. This book bridges the gap between introductory books and source scientific information."What I wanted was an intermediate overview that went into more detail but wasn't written for academics or researchers. When I became a technical diving instructor I started teaching other people about decompression theory. I tried to give an overview of decompression theory at this intermediate level to give my students a better understanding of what was happening during decompression dives. This was always very popular amongst divers who, like me, had always wanted to understand more about the concepts and models underlying decompression theory. I was always being asked if I could recommend a good book which covered this area but as before, there was no such text available. Over time I started giving out notes for the decompression theory portion of my courses and these notes started building. Initially they were just a few pages but the notes became more and more comprehensive and started to cover more and more areas. Eventually they grew into this book".Eurotek 2010 - Winner Publication of Significance Award.TekDive 2014 - Winner Media Award.

The new 2nd Edition of Basic Decompression Theory And Application has been extended, updated, with new material added.  It takes all rudiments of decompression theory and phase mechanics to considerable depth, while focusing on diving applications in an historical perspective. Topics span many disciplines, and the targeted audience is the commercial diver, hyperbaric scientist, doctor, physical scientist, technical diver, and instructor.  Recent developments in diving tables, decompression meters, and decompression management software are presented, and broad model underpinnings are detailed and contrasted.  Testing and validation of modern dual phase approaches to staging for decompression, extended range, altitude, and mixed gas diving are a focus of discussion.  Deep stops, optimal gas switches, and helium mixes are underscored from diver experience, data, and coarse grain principles. References and numerical examples (with solutions) are included for more detail and extended diver analysis.

 

     The monograph is a ten part series, touching upon diving aspects of thermodynamics, pressure and density, flow mechanics, gas kinetics, free and dissolved phase transfer, gas counter transport, nucleation and cavitation, bubbles and surfactants, statistics, DCS and oxygen toxicity risk.  Computational schemes popularly employed in the technical diving sector are developed. New material and updated information are woven into the fabric of the earlier version.  The 1st Edition of this publication was a sellout in the diving community, and the 2nd Edition is much more detailed, comprehensive, and modern in panorama.

 

Chapters include:

 

 Background And History                          Nucleation And Bubbles

 Dissolved Gas Models                              Free Phase Gas Models

 Typical Applications                                Mixed Gases

 Tables And Meters                                   Decompression Risk And Statistics

 Biophysical Issues                                    Modern Summary

Contents, Introduction...1 Chapter 1- Historical Perspective...7, Robert Boyle (1627 - 1691)...7, Rediscovery...8, Caissons Disease...9, Paul Bert (1833-1886)...11, John Scott Haldane (1860-1936)...12, US Navy...15, Robert Workman...16, Professor Albert Buhlmann (1923 - 1994)...17 Chapter 2- Decompression Principles...19, Overview...19, The Air we Breathe...20, The Effects of Pressure...21, Dalton's Law...22, The Lungs...23, Henry's Law...26, Diffusion...26, Gas Transport...28, Perfusion...28, Saturation...29, Tissue Compartments...30, Half Times...30, Supersaturation...32, Critical Supersaturation...34, Controlling Ratio M-Values...34, Ascent Rates...36, No-Stop Dives...39, Bubble Formation...40, Silent Bubbles...40, Safety Stops...41, Decompression Stops...43, Oxygen Window...48 Chapter 3- Decompression Illness...51, Burst Lung...51, Arterial Gas Embolism (AGE )...52, Interstitial Emphysema...52, Pneumothorax...52, Decompression Sickness...52, Decompression Classification...53, Type I...53, Type II...54, Type III...54, Type IV ...55, Reclassification of DCS and AGE ...57, Symptoms of the Bends by Frequency ...59, Time of Onset of Symptoms ...59, Predisposing Factors...60, Dehydration...60, Dive Profiles...61, Repetitive Diving...62, Temperature...62, Obesity...63, Exercise...63, Smoking...65, Age...66, Flying after Diving...66, Reverse Profile...67, Previous Injury...69, PFO...69, Lung Shunts...72, Doppler Bubble Detection...73, Medical implications of DCI...75, First Aid...76, Oxygen...77, 5 Minute Neurological Exam...79, Recompression...81, In-Water Recompression...85, Omitted Decompression...87 Chapter 4- Saturation Diving...89, Development Of Saturation Diving...90, Commercial Saturation Diving...93, Saturation Decompression...93 Chapter 5- Nitrox...95, Using Nitrox...97, Using Nitrox as a Decompression Gas...100, The Oxygen Window Revisited...104 Chapter 6- Deep Stops and Bubble Models...109, Deep Stops...111, Pyle Deep Stops - an Example...113, Gradient Factors...116, Dual Phase (Bubble) Models...118, Individual Bubble Behaviour...120, Multiple Bubble Behaviour...124, Gas Switches and Bubble Models...126, Specific Bubble Models: Thermodynamic Model...127, Varying Permeability Model...129, Critical Volume Algorithm...131, Development of VPM...132, Reduced Gradient Bubble Model...133 Chapter 7- Mixed Gas...135, Choice of Gas...136, Argon...136, Neon...136, Hydrogen...136, Helium...137, Trimix...140, Trimix Decompression...143, Helium in Decompression Gases...147, Isobaric Counter Diffusion...148 Chapter 8- Other Decompression Models...157, RNPL - Slab Diffusion...158, BSAC -'88...160, US Navy Exponential Linear Model...162, Probabilistic Models...163, DCIEM...165, Ratio Deco...168 Chapter 9- Decompression Calculations...171, Compartments, Half Times and Surfacing Ratios...171, Workman M-Values (1965)...172, Buhlmann ...173, ZH-L16A Set of M-Values for Nitrogen (1990)...174, ZH-L16A Half-times, "A" and "B" Values for Nitrogen and Helium...175, Conversion from Workman M-Values to Buhlmann Coefficients...175, The DCAP MM11F6 Model (1988) for Nitrogen...176, Variable Permeability Model (VPM)...177, Alveolar Partial Pressure...177, No Decompression Limits (NDL)...178, Saturation Level...178, Buhlmann...178, Schreiner...178, Ascent Ceiling...178, Decompression Stops...179, Calculating a Decompression Profile...179, Gradient Factors...180, Saturation Diving...180, DCIEM...180, Ratio Deco...181, GUE Ratio Deco Calculations...181, Ratio Set Points...181, First Deep Stop...181, Generic Ratio Deco Calculations...181, Ratio Set Points...181, First Deep Stop...181, Acknowledgements...182, References and Further Reading...183, Index...190 During the last few years technical diving has become much more popular and has moved into mainstream diving. As a result a significant number of recreational divers are moving towards technical diving. Despite this, there are still many misconceptions about what technical diving actually means and what is involved. Introduction to Technical Diving - An Introduction by Mark Powell gives a straightforward overview of technical diving and dispels many of the myths surrounding this area. It explores what is meant by technical diving, what is involved, the risks that arise and how you can move towards this type of diving. Section one describes technical diving in general and illustrates some of the differences between technical and recreational diving as well as explaining some of the things that recreational divers can learn from technical divers. Section two explains some of the ideas behind this form of diving. It defines exactly what we mean by technical diving as well as why it has become so popular. This section then explains how to make a start in technical diving and the type of divers who tend to get into technical diving. For these divers the second section then goes on to explain what to expect from a technical diving course. Finally this section discusses how accident analysis has been used to shape some of the concepts in technical diving as well as some of the mental aspects of this type of diving. The third section then goes on give an overview of technical diving equipment and explains why this is different to the equipment used in recreational diving. There are many different opinions about technical diving equipment and this section of the book lays out the advantages and disadvantages of the various options so that divers can make an informed decision about their equipment choices. Topics such as twinset configuration, Hogarthian gear configuration and choice of stage cylinders are all covered for the open circuit diver. The fourth section covers the various skills required for technical diving are discussed in detail including buoyancy control, trim, tram diving, problem shutdown and valve shutdowns. Section five covers the issues involved in rebreather diving and the various choices available to divers looking to switch to a rebreather. Section six discusses the various aspects of technical dive planning including decompression planning, dealing with narcosis, avoiding oxygen toxicity and gas planning. Finally this section covers some of the various aspects of planning for specific situations such as wreck, cave penetration and mixed gas expedition diving. The book is aimed at anyone who wants to know more about technical diving. Whether you are looking to take a technical diving course, are looking to improve your skills or simply want to find out more about what's involved then this book will provide a comprehensive overview. Even those divers who are not tempted to venture into this area of the sport can benefit from this book as it also discusses what lessons can be learnt from technical diving in order to improve normal recreational diving. The intent of this book is to present a working view of the reduced gradient bubble model (RGBM), decompression mechanics, and applications to technical diving. The focus is RGBM theory and correlations with experiment, lab testing, field-testing, and data. It is directed to the reader with some rudimentary understanding of decompression. Dual phase mechanics, materials, and bubble phenomenology are linked, field testing, data, and validation are discussed, and the physical couplings are presented. Extensive references are appended. Some have called it a revolution in modern diving. The RGBM has already gained widespread acceptance and popularity with growth in prominence, particularly in the deep, decompression, and mixed gas sectors. This is due to released Tables (NAUI), meter implementations (Suunto, Mares, Dacor, Plexus, Hydrospace, Plexus, Zeagle) computer software (GAP, ABYSS, RGBMdiving.com), testing, validation and wholesale positive results and feedback by real divers across all venues. "Deco for Divers provides a comprehensive overview of the principles underlying decompression theory and physiology. Mark Powell has written a book that for the first time allows the average diver to fully understand the principles behind this fascinating and critical aspect of diving. As well as a thorough examination of air decompression the book also addresses decompression using nitrox and mixed gases. It is completely up-to-date and includes information on the latest developments including deep stops and advanced bubble models. Deco for Divers bridges the gap between introductory books and specialist scientific journals and is suitable for new as well as highly experienced divers."--Publisher's website Fully updated and revised. Award winning Deco for Divers provides a comprehensive overview of the principles underlying decompression theory. This book bridges the gap between introductory books and source scientific information. It provides the reader with a clear understanding of the decompression principles which apply to every dive.