Category: Technical Diving Articles
Types of Decompression Sickness (DCS) by Andy Davis Decompression sickness is caused by inert gases leaving solution inside the body and forming bubbles. If allowed to grow sufficiently large, those bubbles present signs and symptoms, which allow DCS to be diagnosed, such as; Type 1: Minor. Localized pain, skin itching (Pruritis) and skin rash (Cutis marmorata) […]
How to Tie a Regulator Bungee Necklace Technical, sidemount and hogarthian configuration scuba divers utilize a regulator bungee necklace for stowage of the short hose back-up. These regulator bungee necklaces are available for purchase in many scuba shops. The manufactured ones are made of rubber, costs are relatively high and there is no option for […]
The Biggest Risk in Technical Diving (and how to avoid it) by Andy Davis There are old divers. And there are bold divers. But there are few old, bold divers. The biggest risk in technical diving is, quite simply, not having the capacity to resolve the next hazardous incident that occurs to you. This applies […]
Prepare Yourself For Technical Diving by Andy Davis Technical diving is increasingly becoming more mainstream as a diving activity; that is a good thing. Many more divers are now opting to pursue tech training as a means to increase the range of their potential diving and enjoy new experiences in their favourite hobby. However, many […]
Goal Setting for Technical Diving Training by Andy Davis Technical diving is a serious endeavour, that requires a significant commitment in respect of money, time and effort. For that reason, very few divers embark on technical diving training without having some sort of plan of what they wish to achieve in the long-term. Setting long-term […]
Subclinical DCS, Decompression Stress and Post-Dive Fatigue by Andy Davis Post-Dive fatigue, malaise, lethargy, sleepiness and decreased vitality is an often-observed consequence of scuba diving. Many divers can relate with this; having felt sluggish and in dire need of a snooze during surface intervals or after diving. Is it really normal and expected? Is it […]
Nitrogen Narcosis – Perceptions of Susceptibility Examining the human factors influencing diver perceptions of susceptibility to nitrogen narcosis. By Andy Davis Nitrogen narcosis is a hyperbaric neurological phenomenon. Its existence, symptoms and onset are known, even if medical science has not yet explained the physiological mechanisms causing it. Individual susceptibility to the effects of nitrogen […]
Sheck Exley’s Razor – The Nature of Limits By R.D. Milhollin (Blog editor’s note: This article was first published in the March-April 1995, issue of Underwater Speleology. I have added it here on my blog to preserve and disseminate further, what I believe to be beneficial insights into overhead and technical diving knowledge). Sheck Exley was one […]
Gradient Factor Comparison Using A Simple 60m Trimix Dive Case-Study By Andy Davis. As a follow-up to my previous article, ‘A Logical Application of Gradient Factors Settings for Open-Circuit Tech Divers‘, I have decided to write a comparative case-study that illustrates the effect that three different gradient factor settings can have on the dynamics of […]
Technical Diving – The Experience Paradox by Andy Davis. Many technical divers assume that acquiring greater training and experience must increase safety. This is a flawed assumption. Accident statistics in technical diving, along with other sporting and industrial fields, show a distinct tendency for elevating risk as significant experience accumulates. The reason is complacency. A […]
A Logical Application of Gradient Factors Settings for Open-Circuit Tech Divers by Andy Davis As an active technical diving instructor for many years, I see many tech divers struggling to use Gradient Factors to their full advantage. This article explains my own systematic and easily applicable approach to setting Gradient Factors for optimal off-gassing effect. […]
The Changing Tech Community Landscape by Andy Davis. Having been actively involved in technical diving for over 15-years as both a diver and instructor, people sometimes ask me how things have changed since I first ‘went to the dark side’. There have been many changes; the equipment and technology used, the understanding of decompression and […]
Are You A Prestigious Diver? by Andy Davis There are many motivations that drive divers to pursue higher level, more advanced qualifications and skills. There are many reasons why advanced divers are attracted to one agency, or methodology, or equipment brand over another. Some divers undertake further training and more ambitious dives because they enjoy […]
Mildly Bent – Decompression Stress and Micro-Bubbles by Andy Davis Sub-Clinical DCS Bubbles occur in our bodies on the ascent from most scuba dives, but those bubbles have to reach a sufficient size before they cause enough immediate harm to present diagnoseable symptoms of DCS. Bubbles of insufficient size to cause clinically identifiable decompression sickness […]
Decompression Sickness And the Immune System by Andy Davis It is known that bubbles within the body trigger an immune system response. For this reason, immune-suppressant drugs are often administered during hyperbaric treatment for decompression sickness. The immune system reacts to bubbles as it would to any foreign body; such as a virus or bacteria. That […]
Performance Development for Technical Divers Observe – Analyze – Adapt by Andy Davis As a technical diving instructor, a primary aspect of my work is the process of observing diver performance (both in my students and their peers across the diving community), analyzing successes and limitations and finding the root causes for them; before adapting […]
Does Nitrogen Narcosis Impairment Persist? by Andy Davis. A new study on nitrogen narcosis challenges the long held presumption that nitrogen narcosis impairment dissipates immediately on ascent from depth. A scientific study, ‘Persistence of Critical Flicker Fusion Frequency Impairment; Evidence of Prolonged Nitrogen Narcosis,’ first published in 2012 in the European Journal of Applied Physiology, by Costantino […]
A Fatal Attempt: Dr Guy Garman’s World Depth Record 2015 Analyzing The Psychological Factors That Can Lead A Team Into A Destructive Goal Pursuit. by Andy Davis On the 15th August 2015, the technical diving community received sad news that the latest World Depth Record attempt, to 1200ft/365m) had ended in tragedy when the participant, […]
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