[Factsheet] The 1908 publication established the first decompression model and the first diving tables, creating the concept of decompression stops based on the maximum depth reached and the dive time (which at the time was opposed to a slow and...

[Factsheet] Following the Biomechanics of Safe Ascents Workshop in 1990, everyone agreed on an ascent rate of 10 m/min. According to Bennet and Elliott, 'Today, an ascent rate of 10 m/min (33 feet per minute) is adopted by a large number of dive comp...

[Factsheet] Deep stops include : Stops at half the maximum depth (also known as "Pyle stops");Stops deeper than those proposed by the desaturation model, due to the setting of gradient factors (GF), in particular with a GFlow lower than GFhigh. More ...

[Factsheet] The density of the gases breathed in during diving is one of the limiting factors, because of the breathing difficulties (WoB: Work of Breathing) and the accumulation of CO2 that it can cause. More information on fact-sheets section.

[Factsheet] Narcosis is 'progressive from 35 to 60 m depth when diving with air, with no threshold effect, and systematic beyond 60 m' More information on fact-sheet section.

[Factsheet] Apart diver training and experience, the maximum depth for diving depends on: A physiological limit linked to the gas breathed (narcosis, hyperoxia, density, DCS); Historical-social-touristic-cultural considerations which may lead certain...

[Factsheet] Reduction Factor (RF) or Gradient Factors (GF) are coefficients (e.g. 90%, 80%...) that can only be used with Haldanian sets of parameters (e.g. U.S. Navy, Bühlmann...) and that allow the M-Values to be reduced in order to increase t...

[Factsheet] In addition to pure technique, you must ensure that your finning has as little impact on the environment as possible. FOUR FUNDAMENTAL RULES The diver must be well balanced (weight, lung volume control, life jacket).Diving horizontal...

[Factsheet] The dive computers display a reference to certification in compliance with different regulations.This does not concern the software, only the pressure, time measurement and interferences.The software is not certified; it is created u...

Le 27 juin 2025, la CMAS était représentée par son vice-président honoraire, Alain Germain, aux cérémonies des 80 ans du CEPHISMER (Marine nationale), créé en 1945 par Philippe Tailliez, Jacques-Yves Cousteau (également président fondateur de la CMAS...

On 27 June 2025, the CMAS was represented by its Honorary Vice-President, Alain Germain, at the 80th anniversary celebrations of CEPHISMER (the French Navy), which was founded in 1945 by Philippe Tailliez, Jacques-Yves Cousteau (who was also the foun...

A new section on CMAS TC website: "Fact Sheets". Many of you are looking for information about diving, how to teach it and the CMAS recommendations. This new section of our website has been created to provide you with an overview of these issues and ...

Recreational Diving Medical Screening System by UNDERSEA & HYPERBARIC MEDICAL SOCIETY with the support of CMAS In 2020, the international Diver Medical Screening Committee (DMSC) released a new diver medical screening system and guidance to the p...

Sharm-El-Sheik (Egypt), May 2025, Mr. Alain Foret was newly elected president of the Technical Committee. With a strong background in diving education and training, he is entrusted with the mission of further developing technical diving worldwid...

From 31 October to 9 November 2024, the city of Monastir in Tunisia hosted the second CMAS/FASST instructor training session, following the 2022 session in Tabarka. This event, organised by the CMAS Technical Committee and in partnership with the Tun...

We are pleased to announce the creation of a new CMAS Four Star Instructor (M4) standard, a prestigious distinction and the highest within the diving instructor community. This new standard honours CMAS Three Star instructors who have demonstrated ex...

This manual serves a vital purpose, aimed directly at instructor trainers and technical committees of the national federations. Its primary goal is to streamline the training process for future CMAS instructors, providing a comprehensive resource for...

It is with deep sadness that we heard today of the passing of our dear friend and colleague Ray Yeates. Up to the recent past Ray, for many years was the President of Comhairle Fo-Thuinn, the Irish Underwater Council. He held the position of Secretar...

Over 15-day an intensive CMAS course was carefully designed to encompass all the crucial aspects of diving for CMAS 2 and 3 Star Instructors, ensuring a comprehensive exploration of fundamental teaching techniques to advanced safety measures and risk...

The manual is intended for instructor trainers and all local technical committees. Questions about this manual can be directed to me or CMAS TC Director Standards & Equivalencies mr. Abdelaziz Rezik. I hope that this manual will make it easier fo...