A recent analysis of the DAN database has yielded a surprising result: women appear to have a significantly higher risk of decompression sickness (DCS) than men. The analysis is based on nearly 128,000 dives by approximately 5,900 divers. Overall, DCS was reported in about 0.49% of dives. In the data, DCS occurred about three times more frequently in women than in men; statistical modeling even yielded an odds ratio of 4.63—a more than fourfold higher risk for women! How is

What began as my personal programming project is now available to everyone: Dekoplaner — a dive planner from Switzerland based on the Bühlmann ZHL-16C model, the globally established standard for decompression calculations. Dekoplaner deliberately focuses on the essentials: transparent and easy-to-understand calculations using classic gradient factors (GF low / GF high)—without unnecessary additional parameters. Dekoplaner is a powerful yet affordable all-rounder for planning

Anyone who dives using the Bühlmann model—which is practically all technically oriented divers using most modern computers—cannot avoid gradient factors (GF). But the question keeps coming up: Should no-decompression limit be calculated using GF low or GF high? This is where GF high plays a role. Foto: Karin Aggeler What does no-decompression limit actually mean? No-decompression limit means that during a dive, you can ascend directly from depth to the surface without exceedi

Case vignette: A 49-year-old, very experienced diver undertook a dive in a Swiss lake with his rebreather (JJ-CCR) in autumn. The water temperature was around 10 °C. After only about 10 minutes, he felt increasing shortness of breath, which rapidly worsened. After about 20 minutes, he had to abort the dive as an emergency. The diver had remained within no-decompression limits (maximum depth 30 m, O₂ set point 1.3 bar). At the surface, he was no longer able to remove his equip

From a medical point of view, helium is of little relevance outside of diving. Accordingly, its kinetics have been insufficiently studied in comparison to other inert gases used in medical research and diagnostics, for example as tracers (1). To date, the helium algorithms used in diving medicine are based predominantly on the data set published by Bühlmann. Foto: Karin Aggeler Helium in the Bühlmann model According to Bühlmann, the diffusion rate of helium is 2.65 times high

A 50-year-old diver went diving in a Swiss lake with his closed-circuit rebreather (CCR). The plan was to dive to a depth of around 55 meters with a bottom time of approximately 20 minutes (time until leaving the depth). Compressed air was used as the diluent, at a constant oxygen partial pressure of 1.3 bar. The last decompression stop was at 6 meters. The diver complied with all decompression requirements and ended the dive after a total of 54 minutes. However, about 30 min

An experienced recreational diver conducted a dive to a depth of 30 m in a Swiss lake within the no-decompression limit. During the ascent, he suddenly noticed impaired vision in his right eye. After surfacing, his vision was blurred and foggy in both eyes, whereupon he was given oxygen due to suspicion of a diving accident. After just ten minutes, his vision was completely restored. The diver reported having experienced similar problems with his right eye during previous div

NOAA guidelines for limiting oxygen toxicity in diving date back to the 1970s and 1980s – a time when rebreather technology, digital sensors and today's diving profiles were still a long way off. Nevertheless, these early, deliberately conservative values formed the basis of all safety guidelines for decades. With the current NOAA revision, these limits are now being fundamentally revised for the first time. The new recommendations on CNS oxygen toxicity take into account cur

I was recently asked by a diver whether it makes sense that his diving school requires him to undergo an echocardiography (heart...

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When divers talk about underwater risks, the conversation often centers on decompression sickness or oxygen toxicity. But there’s...

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Diving with oxygen-enriched air – known as Nitrox or EAN (Enriched Air Nitrox) for short – has become established in recreational diving...

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The article “Of Bubbles and Dive Profiles - One Diver's Journey into Personalized Decompression” in InDEPTH Magazine describes the...

New recommendations for screening cardiac right-to-left shunts - especially for persistent foramen ovale (PFO) - in divers have recently...

In our diving school, we have recently discussed the topic of compressed air dives to depths of over 40 meters on several occasions. A...