{"id":4325,"date":"2015-07-14T15:37:09","date_gmt":"2015-07-14T07:37:09","guid":{"rendered":"http:\/\/scubatechphilippines.com\/scuba_blog\/?p=4325"},"modified":"2024-05-14T10:48:45","modified_gmt":"2024-05-14T02:48:45","slug":"gradient-factors-m-values","status":"publish","type":"post","link":"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/","title":{"rendered":"Gradient Factors Explained By Matti Antilla Ph.d"},"content":{"rendered":"\n<h1 class=\"wp-block-heading\">Gradient Factors Explained<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">I have reproduced this excellent article <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a> explained by Matti Anttila in case the original website goes down. It is published here for educational purposes.<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 ez-toc-wrap-center counter-hierarchy ez-toc-counter ez-toc-transparent ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title ez-toc-toggle\" style=\"cursor:pointer\">Article Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#Gradient-factors-explained-by-Matti-Anttila-Phd\" >Gradient factors explained by Matti Anttila Ph.d<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#DECOMPRESSION-THEORY-HISTORY\" >DECOMPRESSION THEORY HISTORY<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#Paul-Bert\" >Paul Bert<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#John-Scott-Haldane\" >John Scott Haldane<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#Robert-Workman\" >Robert Workman<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#Dr-Albert-A-Buhlmann\" >Dr. Albert A. B\u00fchlmann<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#DECOMPRESSION-THEORY-BASICS\" >DECOMPRESSION THEORY BASICS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#TISSUE-SATURATION-AND-ASCENT-CEILING\" >TISSUE SATURATION AND ASCENT CEILING<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#M-VALUES\" >M-VALUES<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#Become-A-Shearwater-Power-User-eBook\" >Become A Shearwater Power User! (eBook)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#GRADIENT-FACTORS\" >GRADIENT FACTORS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#PRACTICAL-APPLICATIONS-AND-SAFE-DIVING-HABITS\" >PRACTICAL APPLICATIONS AND SAFE DIVING HABITS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#About-the-author-Matti-Anttila\" >About the author Matti Anttila<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#GRADIENT-FACTOR-REFERENCES\" >GRADIENT FACTOR REFERENCES<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-m-values\/#Become-A-Shearwater-Power-User-eBook-2\" >Become A Shearwater Power User! (eBook)<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Gradient-factors-explained-by-Matti-Anttila-Phd\"><\/span>Gradient factors explained by Matti Anttila Ph.d<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Remember your first diving classes and the lesson about bubbling soda bottle and too rapid ascents? No matter how deeply you study the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> theory, this soda bubble analogy is still valid. However, it\u2019s time to introduce some more fundamentals of the issue. But let\u2019s start from the history:<\/p>\n\n\n\n<div id=\"scuba-869537417\" class=\"scuba-b4-h2-2 scuba-entity-placement\" style=\"margin-top: 10px;margin-bottom: 10px;\"><div class=\"scuba-adlabel\">Sponsored Link<\/div><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-9354033900485448\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:block;\" data-ad-client=\"ca-pub-9354033900485448\" \ndata-ad-slot=\"2393012471\" \ndata-ad-format=\"auto\" data-full-width-responsive=\"false\"><\/ins>\n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"DECOMPRESSION-THEORY-HISTORY\"><\/span>DECOMPRESSION THEORY HISTORY<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Decompression<\/a> theory is a relatively old science. Already in late 1800\u2019s, French physiologist Paul Bert (1833-1886) discovered <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">decompression sickness<\/a> and the need for <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> stops and slow ascend speed. <\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Paul-Bert\"><\/span>Paul Bert<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Bert also studied the effects of oxygen to the humans, as he was more interested in the physiological effects of mountaineering and hot air ballooning. He also extended his studies to cover high pressure environments, and found out later about <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/oxygen-toxicity-thalmann\/\">oxygen toxicity<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bert made a conclusion that high oxygen partial pressures affect humans chemically, not mechanically, as he described the causes of Central <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-diving-stress-management-and-diver-panic\/\">Nervous<\/a> System (CNS) <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/oxygen-toxicity-thalmann\/\">oxygen toxicity<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When Bert studied air and nitrogen, he correctly determined the cause of the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">Decompression Sickness<\/a> (<a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a>) to be caused by the nitrogen bubbles in the blood and other tissues (mechanical effects). Bert also did experiments on recompression therapy and oxygen administration in <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> cases. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The most famous of Bert\u2019s books is \u201cLa Pression barometrique\u201d 1 , published in 1878, which dealt with the human physiology in low and high air-pressures.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"John-Scott-Haldane\"><\/span>John Scott Haldane<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">While Bert laid the fundamentals to the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> studies, it was John Scott <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Haldane<\/a> (1860-1936), a Scottish physiologist who approached the problem of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> theory with more scientific approach. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In 1905, <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Haldane<\/a> was appointed by the Royal Navy to perform research about Navy\u2019s diving operations. His <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/flow-state-scuba-diving-skills\/\">focus<\/a> was to study the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">decompression sickness<\/a> and how it could be avoided. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Haldane<\/a> performed several tests and studied the effects of compressed air at depth, and in 1908 he published the results of his tests in the Journal of Medicine 2. This article also contained his diving tables.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Haldane<\/a> is considered to be the father of modern <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> theory. In his research, he made an important conclusion that a diver could surface from an indefinitely long 10m\/33ft dive without <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">From this result, he determined that human body could tolerate pressure change with a factor of 2:1 (the pressure in 10m\/33ft is 2 ATA, while on surface it is 1 ATA). Later this number was refined to be 1.58:1 by <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Robert Workman<\/a>. <\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Robert-Workman\"><\/span>Robert Workman<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> was an M.D. and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> researcher in U.S. Navy during 1960\u2019s. He studied systematically the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression model<\/a> that was used in the U.S. Navy and which was then based on Haldane\u2019s research. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In addition to refining the tissue pressure ratio, <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> found out that the ratio varied by tissue type (hence the term \u201ctissue compartment\u201d or TC, representing different half-times, e.g. speed of gas dissolving) and depth.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Dr-Albert-A-Buhlmann\"><\/span>Dr. Albert A. B\u00fchlmann<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Dr. Albert A. <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> (1923-1994) from Z\u00fcrich developed <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> theory further. During his long research career, he extended the number of tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartments<\/a> to 16, which was the basis of his ZH-L16 <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression model<\/a> (\u201cZH\u201d as Z\u00fcrich, \u201cL\u201d as Linear and \u201c16\u201d for the number of TCs). <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The first set of ZH-L16 tables was published in 1990 (previous tables 3, published earlier, contained smaller amount of TCs).<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"DECOMPRESSION-THEORY-BASICS\"><\/span>DECOMPRESSION THEORY BASICS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Let\u2019s start from basics: A diver goes down and breathes compressed air from his\/her cylinder. Air contains nitrogen, which, as an inert gas, dissolves into the diver\u2019s tissues. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the diver starts ascending, the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">ambient pressure<\/a> decreases and dissolved nitrogen transfers from other tissues to the blood, from there to the lungs, and finally leaves the body with each exhale cycle. Simple as that, is it?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In recreational diving, no <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> dives are being conducted. Divers are told to stay within their no-decompression <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/sheck-exley-razor-limits-diving-caves\/\">limits<\/a> (<a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/difference-safety-stops-decompression-stop-scuba-diving\/\">NDL<\/a>) of bottom time. This <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/difference-safety-stops-decompression-stop-scuba-diving\/\">NDL<\/a> is shown in diving tables, and besides that, divers must stay within a certain ascent speed. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This information is generally enough for most divers, but what happens when we exceed the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/difference-safety-stops-decompression-stop-scuba-diving\/\">NDL<\/a> and start accumulating <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> time?<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"TISSUE-SATURATION-AND-ASCENT-CEILING\"><\/span>TISSUE SATURATION AND ASCENT CEILING<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When we dive, we always have an invisible ceiling above us. This ceiling is a depth, which we can ascend to without getting <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> symptoms (generally speaking). The ceiling is based on the amount of dissolved inert gas in our tissues.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 1 (below) represents a typical <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> dive profile with multiple <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> stops. Before the dive, your \u201cceiling\u201d is in fact negative depth (above surface), meaning that your tissues could tolerate certain overpressure gradient. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As the run time increases and diver spends time at the bottom, the ceiling depth goes down and starts limiting the ascent possibilities, generating the need for <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In fact, some <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> software indicates the ceiling depth when user types in the desired dive levels. Diving computers indicate the ceiling as the deepest required <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> depth.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"844\" height=\"436\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image001.png\" alt=\"\" class=\"wp-image-26281\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image001.png 844w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image001-300x155.png 300w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image001-768x397.png 768w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image001-250x129.png 250w\" sizes=\"(max-width: 844px) 100vw, 844px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Figure 1: A typical <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> dive profile with ceiling line visible. Numbers represent different phases (see phases also in Figure 2).<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the ascent starts, the diver can not ascend above the ceiling without risking the possibility of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">decompression sickness<\/a>. The <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> stops are clearly visible in the dive profile in Figure 1. The closer one goes to the ceiling, the less margin of safety remains. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The ceiling depth does not yet indicate on-gassing or off-gassing. <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> used 16 tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartments<\/a> to model inert gas dissolving in our body. These <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartments<\/a> either take more <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/confusion-deep-stops-erik-baker\/\">dissolved gas<\/a> in (on-gassing) or expel <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/confusion-deep-stops-erik-baker\/\">dissolved gas<\/a> out (off-gassing). <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The ceiling depth indicates the pressure change from current depth, in which the leading <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartment<\/a> off-gasses so fast, that further increased pressure drop<br \/>would risk the possibility of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 2 illustrates these 16 tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartments<\/a> during the dive, presented in Figure 1. A tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartment<\/a> (TC) has reached its saturation point when it is 100% full. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">During the ascent phase, a TC can go supersaturated (exceeds 100%). The key of the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> is to be supersaturated, but not so much that the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/confusion-deep-stops-erik-baker\/\">dissolved gas<\/a> would form excess bubbles<br \/>to our tissues and blood.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"608\" height=\"526\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-2.jpg\" alt=\"\" class=\"wp-image-26283\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-2.jpg 608w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-2-300x260.jpg 300w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-2-173x150.jpg 173w\" sizes=\"(max-width: 608px) 100vw, 608px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Figure 2: An example of inert gas loading in tissues. Pressure in tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartment<\/a> is indicated as percents, 100% being <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">ambient pressure<\/a>.<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As shown, the amount of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/confusion-deep-stops-erik-baker\/\">dissolved gas<\/a>, or specifically the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-laws-for-diving-physics\/\">partial pressure<\/a> of the dissolved inert gas in our tissues, tends to follow the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">ambient pressure<\/a> in which we are during the dive. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The bigger the pressure difference (i.e. pressure gradient), the faster the gas dissolves, in both directions. <\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This leads to an obvious question: Why not just come up? What are the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/sheck-exley-razor-limits-diving-caves\/\">limits<\/a> of supersaturation, and how are they defined?<\/p>\n\n\n\n<div id=\"scuba-2179704541\" class=\"scuba-b4-h2-3 scuba-entity-placement\" style=\"margin-top: 10px;margin-bottom: 10px;\"><div class=\"scuba-adlabel\">Sponsored Link<\/div><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-9354033900485448\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:block;\" data-ad-client=\"ca-pub-9354033900485448\" \ndata-ad-slot=\"6151212517\" \ndata-ad-format=\"auto\" data-full-width-responsive=\"false\"><\/ins>\n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"M-VALUES\"><\/span>M-VALUES<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Back to the history: <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Robert Workman<\/a> introduced the term <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a>, which means Maximum inert gas pressure in a hypothetical tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartment<\/a> which it can tolerate without <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As mentioned, <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Haldane<\/a> found out in his research that <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> is 2, and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> refined it to be 1.58 (this number comes from pressure change from 2 ATA to 1 ATA, and taking into account that air has 79% inert gases, mainly nitrogen).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> determined the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> using depths (pressure values) instead of ratios of pressure, which he then used to form a linear projection as a function of depth. The slope of the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line is called <strong>?<\/strong>M (delta-M) and it represents the change of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> with a change in depth (depth pressure).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> used the same method than <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> to express the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a>, but instead of using the depth pressure (relative pressure), he used absolute pressure, which is 1 ATA higher at depth. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This difference is shown in Figure 3, where Workman\u2019s <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line goes above <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a>\u2019s <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"613\" height=\"544\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image011.png\" alt=\"\" class=\"wp-image-26284\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image011.png 613w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image011-300x266.png 300w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image011-169x150.png 169w\" sizes=\"(max-width: 613px) 100vw, 613px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Figure 3: Comparison of different <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> lines.<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 3 shows a comparison between <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> lines. A more detailed explanation can be found in literature 4, but it is easy to spot the greatest differences: while <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line is steeper than <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line, there is also less margin for safety. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> also allow higher supersaturation than <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a>\u2019s.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To make things a bit more complex, it should be noted that while the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> vary by tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartment<\/a>, also two sets of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> are used for each TC; <\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>M?-values (of depth pressure, indicating surfacing pressure. M? is pronounced \u201cM naught\u201d) <\/li>\n\n\n\n<li><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> of pressure ratio (<strong>?<\/strong>M, \u201cdelta-M\u201d values)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Workman<\/a> defined the relationship of these different <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> as:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">M = M? + <strong>?<\/strong>M \u00b7 d, where:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">M = <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-laws-for-diving-physics\/\">partial pressure<\/a> limit for each TC (in ATA units)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">M? = <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-laws-for-diving-physics\/\">partial pressure<\/a> limit at sea level for each TC (ATA)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>?<\/strong>M = increase of M per depth, defined for each TC (ATA\/m)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">d = depth (m).<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"585\" height=\"88\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/M-Values.jpg\" alt=\"\" class=\"wp-image-26285\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/M-Values.jpg 585w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/M-Values-300x45.jpg 300w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/M-Values-250x38.jpg 250w\" sizes=\"(max-width: 585px) 100vw, 585px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">These sets of values are listed in literature4. However, they concern the same thing: maximum allowed overpressure of the tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartments<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is also important to know, that <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">decompression illness<\/a> (<a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/underserved-bends-unexplained-dcs-hits\/\">DCI<\/a>) does not exactly follow the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a>. More <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/underserved-bends-unexplained-dcs-hits\/\">DCI<\/a> occurs at and above the pressures represented by the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a>, and less sickness occurs when divers stay well below the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-dots\"\/>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-center\"><span class=\"ez-toc-section\" id=\"Become-A-Shearwater-Power-User-eBook\"><\/span><strong>Become A Shearwater Power User! (eBook)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<div class=\"wp-block-columns is-not-stacked-on-mobile is-layout-flex wp-container-core-columns-is-layout-995f960e wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-stretch is-layout-constrained wp-block-column-is-layout-constrained\" style=\"flex-basis:50%\">\n<figure class=\"wp-block-image alignright size-large is-resized\"><a href=\"https:\/\/www.buymeacoffee.com\/andydavistech\/e\/233171\" target=\"_blank\" rel=\"noreferrer noopener\"><img decoding=\"async\" width=\"652\" height=\"1024\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-652x1024.jpg\" alt=\"Shearwater Power User Settings GF Gradient Factors eBook\" class=\"wp-image-26260\" style=\"width:250px\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-652x1024.jpg 652w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-191x300.jpg 191w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-768x1206.jpg 768w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-96x150.jpg 96w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image.jpg 794w\" sizes=\"(max-width: 652px) 100vw, 652px\" \/><\/a><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top has-luminous-vivid-amber-background-color has-background is-content-justification-left is-layout-constrained wp-container-core-column-is-layout-aa397865 wp-block-column-is-layout-constrained\" style=\"flex-basis:40%\">\n<p class=\"has-text-align-center has-luminous-vivid-amber-background-color has-background wp-block-paragraph\" style=\"line-height:1.3\">An Illustrated Guide to <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a> and Advanced <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/best-technical-diving-computer\/\">Shearwater<\/a> Computer Settings for safe scuba diving.<\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" style=\"line-height:1.3\"><strong>42 Pages. Printable PDF format. Fully Illustrated.<\/strong> <strong>$9<\/strong><\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" style=\"font-style:normal;font-weight:700;line-height:1\"><strong><a href=\"https:\/\/www.buymeacoffee.com\/andydavistech\/e\/233171\" target=\"_blank\" rel=\"noreferrer noopener\"><strong><\/strong><\/a><\/strong><strong><a href=\"https:\/\/www.buymeacoffee.com\/andydavistech\/e\/233171\" target=\"_blank\" rel=\"noreferrer noopener\">Become A Shearwater Power User eBook<\/a><\/strong><\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" style=\"font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.313), 18px);\">As featured on the <a href=\"https:\/\/www.youtube.com\/watch?v=zTjVXugn-m0\" target=\"_blank\" rel=\"noreferrer noopener\">DiveTalk Podcast<\/a><\/p>\n<\/div>\n<\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-dots\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"GRADIENT-FACTORS\"><\/span>GRADIENT FACTORS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a> are meant to offer conservatism settings for <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a>\u2019s <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression model<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As mentioned in the previous chapter, <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line sets a limit which is not supposed to be exceeded during ascent and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a>. However, as no <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression model<\/a> can positively prevent all <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> cases, and because both dives and divers are individual, additional safety margin should be applied.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As shown in Figure 3, ascent and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> occurs between the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Ambient Pressure<\/a> line. Inert gas pressure in tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartments<\/a> must exceed the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">ambient pressure<\/a> to enable off-gassing. On the other hand, we do not want to go too close to the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line for safety reasons. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a> define the conservatism here. The <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factor<\/a> defines the amount of inert gas supersaturation in leading tissue <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartment<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Thus, GF 0% means that there is no supersaturation occurring and inert gas <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-laws-for-diving-physics\/\">partial pressure<\/a> equals <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">ambient pressure<\/a> in leading <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">compartment<\/a> (Note: The leading TC is not necessarily the fastest TC!). <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">GF 100% means that <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> is being done in a situation where the leading TC is at its <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a>\u2019s <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line and risk for <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> is far greater than using lower GF. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">(<em>Note: Sometimes, especially in equations and calculations, GF\u2019s may be numbered as 0.00 \u2026 1.00 instead of percentage. However, these are effectively the same thing as 100% = 1<\/em>)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Some diver\u2019s did not like the idea of using the same conservatism factor throughout the ascent. Instead of having one GF, there was need to change the safety margin during the ascent. This led to two GF values; \u201c<em>GF Low<\/em>\u201d and \u201c<em>GF High<\/em>\u201d. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Low <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factor<\/a> defines the first <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> stop, while High <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factor<\/a> defines the surfacing value. <\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Using this method, the GF actually changes throughout the ascent. This is illustrated in Figure 4, where GF Low and GF High forms start and end points to a <strong><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factor<\/a> line<\/strong>. In that graph, <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> starts when the inert gas <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-laws-for-diving-physics\/\">partial pressure<\/a> in diver\u2019s TC\u2019s reaches 30% of the of the way between <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Ambient Pressure<\/a> line and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Then the diver spends time in that stop until <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-laws-for-diving-physics\/\">partial pressure<\/a> drops in the TC\u2019s enough for enabling ascent to next stop, which again has a bit higher GF. These two GF values are often written as \u201c<em>GF Low-%<\/em> \/ <em>High-%<\/em>\u201d, e.g. GF 30\/80, where 30% is GF Low value and 80% GF High value.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"903\" height=\"754\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image013.png\" alt=\"\" class=\"wp-image-26286\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image013.png 903w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image013-300x250.png 300w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image013-768x641.png 768w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image013-180x150.png 180w\" sizes=\"(max-width: 903px) 100vw, 903px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Figure 4: One-tissue model of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a>. Graph starts from top right and goes left down, staying between the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">ambient pressure<\/a> line and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factor<\/a> (GF) line. <\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">GF line stays below the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line and forms the safety margin for the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a>. Pure <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a><br \/>would follow the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-value<\/a> line (GF 100\/100).<\/p>\n\n\n\n<div id=\"scuba-3415111731\" class=\"scuba-b4-h2-4 scuba-entity-placement\" style=\"margin-top: 10px;margin-bottom: 10px;\"><div class=\"scuba-adlabel\">Sponsored Link<\/div><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-9354033900485448\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:block;\" data-ad-client=\"ca-pub-9354033900485448\" \ndata-ad-slot=\"2954736365\" \ndata-ad-format=\"auto\" data-full-width-responsive=\"false\"><\/ins>\n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div><h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"PRACTICAL-APPLICATIONS-AND-SAFE-DIVING-HABITS\"><\/span>PRACTICAL APPLICATIONS AND SAFE DIVING HABITS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">No <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression model<\/a> can positively prevent divers getting hit. <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> do not represent any hard line between \u201cno <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> symptoms\u201d and \u201cgetting hit\u201d. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In fact, modern <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> science has proven that there might be bubbles present in our tissues even when there are no <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> symptoms after a dive. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">M-values<\/a> neither represent a bubble-free situation, but tolerable amount of \u201csilent\u201d bubbles in tissues.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"603\" height=\"576\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image015.png\" alt=\"\" class=\"wp-image-26287\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image015.png 603w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image015-300x287.png 300w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/image015-157x150.png 157w\" sizes=\"(max-width: 603px) 100vw, 603px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Figure 5: <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/sub-clinical-decompression-sickness-stress-micro-bubbles\/\">Silent bubbles<\/a> are present in our tissues even when no <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> symptoms are present. It is important to know personal safety margin and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/underserved-bends-unexplained-dcs-hits\/\">individual susceptibility<\/a> to <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a>.<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is important to understand that certain dives and different people may need different safety margins. Therefore it is good to know the practical differences between dive plans where different <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a> are used. Let\u2019s take another example:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A diver goes to 50m\/165ft for 20 minutes bottom time, using <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/why-do-deep-divers-use-helium\/\">Trimix<\/a> 18\/45 (18% oxygen, 45% <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/why-do-deep-divers-use-helium\/\">helium<\/a>) as back gas, and oxygen for <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> from 6m (20ft) on. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/diving-descent-speed-co2-narcosis-gas-density\/\">Descent rate<\/a> is 15m\/min (50ft\/min) and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/best-ascent-speed-scuba-diving\/\">ascent rate<\/a> is 10m\/min (33ft\/min). <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Decompression<\/a> algorithm is based on <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">ZH-L16B<\/a> and the different <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> tables, based on five different GFs, are shown in Table 1.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"601\" height=\"299\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-6.jpg\" alt=\"\" class=\"wp-image-26288\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-6.jpg 601w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-6-300x149.jpg 300w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/05\/Figure-6-250x124.jpg 250w\" sizes=\"(max-width: 601px) 100vw, 601px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Table 1: <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Decompression<\/a> tables for 50m (165ft) \/ 20min using different <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These GF parameters are commonly used for different types of dives (e.g. <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/testing-ccr-rebreather-liberty-triton-sidewinder\/\">rebreather<\/a>, deep\/cold dives, default values in some <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> SW) and GF 100\/100 is shown here as a reference, since it is pure <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a> table (containing no margin, so it is also not very safe!). <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>As clearly shown in Table 1, low GF Low numbers generate <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/confusion-deep-stops-erik-baker\/\">deeper stops<\/a>. <\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In fact, some divers use GF Low value of 10% to generate \u201cdeep stops\u201d 5. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/deep-stops-richard-pyle\/\">Deep stops<\/a>, also called \u201c<em><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/confusion-deep-stops-erik-baker\/\">Pyle<\/a> stops<\/em>\u201d, are a means to reduce <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/sub-clinical-decompression-sickness-stress-micro-bubbles\/\">micro-bubbles<\/a> during deeper phase of ascent. However, during <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/deep-stops-richard-pyle\/\">deep stops<\/a>, many slower tissues are still on-gassing and thus total <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> time will increase (but again, safety is worth for some added hangtime!). <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Small GF High values generate longer shallow stops, as also seen in Table 1.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">On long <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> dives, safety margins not only contribute to preventing of <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a>, but also to <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-planning-management-divers\/\">gas planning<\/a>, logistics and equipment considerations. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A good diver adapts his\/her personal <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a> according to personal fitness, environment and dive type. No matter which diving gear you use, <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> and need for conservatism follows your plan!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is easy to modify the dive plan even drastically by using different <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">gradient factors<\/a>. Most modern <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> software provides either conservatism settings (in verbal terms or numbers) or <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">gradient factors<\/a>. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A diver can modify the total dive time easily by even tens of minutes with these settings, not to mention also the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> gas needed. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But this is also a pitfall; consider a situation where <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> software indicates that you need an intermediate <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> mix fill pressure which is just above your <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/scuba-gas-planning-management-divers\/\">cylinder capacity<\/a> (including margins). <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now, an easy but dangerous choice would be altering the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">gradient factors<\/a> so that the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> time decreases, leading to lower <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> gas need.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Divers using computers, which have user-configurable <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">gradient factors<\/a>, should understand how modifying their GF\u2019s will affect to their <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> profiles. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Too many divers simply use the default settings or copy their GF parameters from other divers or even from the Internet, no matter what kind of a dive they are doing. Some divers have higher susceptibility to <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">DCS<\/a> and some dives are physically more demanding than others. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Although the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">gradient factor<\/a> method provides substantial flexibility in controlling the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">decompression<\/a> profiles and thus the dive plan and gas logistics, it just might be worth to hang there a bit longer sometimes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As always in diving, it remains YOUR responsibility to choose the <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">gradient factors<\/a> and conservatism appropriate for you!<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"About-the-author-Matti-Anttila\"><\/span>About the author: Matti Anttila<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Matti Anttila is an engineer with a M.Sc. degree in technical physics and Ph.D. in spaceflight instrumentation, so diving science is close to his heart. He was trained as a minehunter diver in the Finnish Navy in 1995 using semi-closed rebreathers. In the late 1990\u2019s he began teaching <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/what-is-technical-diving\/\">technical diving<\/a> in Finland, and currently he is a <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/why-do-deep-divers-use-helium\/\">trimix<\/a> instructor trainer with IANTD, in addition to being on their Board of Advisors.by Matti Anttila,Ph.D.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"GRADIENT-FACTOR-REFERENCES\"><\/span>GRADIENT FACTOR REFERENCES<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Bert, Paul: <em>La Pression barom\u00e9trique, recherches de physiologie exp\u00e9rimentale<\/em>, 1878<\/li>\n\n\n\n<li>Boycott, A.E., Damant, G.C.C., and <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Haldane<\/a>, J.S: <em>The Prevention of Compressed Air Illness<\/em>, The Journal of Medicine (Journal of Hygiene, Volume 8, (1908), pp.342-443.)<\/li>\n\n\n\n<li><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">B\u00fchlmann<\/a>, Albert A.:<em> <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Decompression<\/a> \u2013 <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/types-decompression-sickness-dcs\/\">Decompression Sickness<\/a><\/em>. Berlin:Springer-Verlag, 1984.<\/li>\n\n\n\n<li><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Baker<\/a>, Erik C.: <em><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Understanding M-values<\/a><\/em><\/li>\n\n\n\n<li><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/understanding-m-values-eric-baker\/\">Baker<\/a>, Erik C.:<em><a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/confusion-deep-stops-erik-baker\/\"> Clearing Up The Confusion About &#8220;Deep Stops<\/a><\/em>&#8220;<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-dots\"\/>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-center\"><span class=\"ez-toc-section\" id=\"Become-A-Shearwater-Power-User-eBook-2\"><\/span><strong>Become A Shearwater Power User! (eBook)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<div class=\"wp-block-columns is-not-stacked-on-mobile is-layout-flex wp-container-core-columns-is-layout-995f960e wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-stretch is-layout-constrained wp-block-column-is-layout-constrained\" style=\"flex-basis:50%\">\n<figure class=\"wp-block-image alignright size-large is-resized\"><a href=\"https:\/\/www.buymeacoffee.com\/andydavistech\/e\/233171\" target=\"_blank\" rel=\"noreferrer noopener\"><img decoding=\"async\" width=\"652\" height=\"1024\" src=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-652x1024.jpg\" alt=\"Shearwater Power User Settings GF Gradient Factors eBook\" class=\"wp-image-26260\" style=\"width:250px\" srcset=\"https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-652x1024.jpg 652w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-191x300.jpg 191w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-768x1206.jpg 768w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image-96x150.jpg 96w, https:\/\/scubatechphilippines.com\/scuba_blog\/wp-content\/uploads\/2024\/03\/Shearwater-Settings-Book-Cover-Image.jpg 794w\" sizes=\"(max-width: 652px) 100vw, 652px\" \/><\/a><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top has-luminous-vivid-amber-background-color has-background is-content-justification-left is-layout-constrained wp-container-core-column-is-layout-aa397865 wp-block-column-is-layout-constrained\" style=\"flex-basis:40%\">\n<p class=\"has-text-align-center has-luminous-vivid-amber-background-color has-background wp-block-paragraph\" style=\"line-height:1.3\">An Illustrated Guide to <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/gradient-factors-dummies\/\">Gradient Factors<\/a> and Advanced <a href=\"https:\/\/scubatechphilippines.com\/scuba_blog\/best-technical-diving-computer\/\">Shearwater<\/a> Computer Settings for safe scuba diving.<\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" style=\"line-height:1.3\"><strong>42 Pages. Printable PDF format. Fully Illustrated.<\/strong> <strong>$9<\/strong><\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" style=\"font-style:normal;font-weight:700;line-height:1\"><strong><a href=\"https:\/\/www.buymeacoffee.com\/andydavistech\/e\/233171\" target=\"_blank\" rel=\"noreferrer noopener\"><strong><\/strong><\/a><\/strong><strong><a href=\"https:\/\/www.buymeacoffee.com\/andydavistech\/e\/233171\" target=\"_blank\" rel=\"noreferrer noopener\">Become A Shearwater Power User eBook<\/a><\/strong><\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" style=\"font-size:clamp(14px, 0.875rem + ((1vw - 3.2px) * 0.313), 18px);\">As featured on the <a href=\"https:\/\/www.youtube.com\/watch?v=zTjVXugn-m0\" target=\"_blank\" rel=\"noreferrer noopener\">DiveTalk Podcast<\/a><\/p>\n<\/div>\n<\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-dots\"\/>\n","protected":false},"excerpt":{"rendered":"<p>Gradient Factors Explained I have reproduced this excellent article Gradient Factors explained by Matti Anttila in case the original website goes down. It is published here for educational purposes. Gradient factors explained by Matti Anttila Ph.d Remember your first diving classes and the lesson about bubbling soda bottle and too rapid ascents? No matter how [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":4326,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[288],"tags":[557,197,351,497,204,277],"class_list":["post-4325","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technical-diving-theory","tag-buhlmann-zhl-16-decompression-algorithm","tag-decompression","tag-diving-decompression-theory-m-values","tag-gradient-factors-for-diving","tag-scuba-diving-theory","tag-technical-diving"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":7}},"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.2 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Gradient Factors Explained By Matti Antilla Ph.d - Andy Davis Sidemount Technical Wreck Diving Blog<\/title>\n<meta name=\"description\" content=\"Gradient factors explained by Matti Antilla Ph.d. 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