Scuba & Technical Diving Reference

The Gas
We Breathe

A complete reference for the serious diver

Gas physics from Boyle's Law to trimix planning. Equipment from 1943 to today. Dive sites mapped worldwide. Training agencies compared. Planning tools, marine life, and the history of the sport — independent, manufacturer-neutral, free.

290+ Models documented
8 Gas physics topics
1943 Earliest reference

About The Gas We Breathe

This reference directory accompanies the book The Gas We Breathe — a comprehensive exploration of the history, technology, and people behind the equipment that made recreational and technical scuba diving possible.

From Émile Gagnan's 1943 demand valve to the present-day Shearwater Perdix and Garmin Descent, every major manufacturer and model is documented with full history and technical context. Independent, thorough, and free from manufacturer influence.

The Education section builds a complete gas physics curriculum — from Boyle's Law through real gas behaviour, Dalton's Law, and partial pressure planning — with interactive simulators for every topic.

How the directory works

Each section is fully searchable and filterable — by status (current or historic), manufacturer, depth, experience level or site type. The Equipment Reference covers every major piece of scuba equipment with consistent fields for introduction date, technical specification, and historical context.

Dive site data includes GPS coordinates, depth profiles, best season, and links to underwater footage. Planning tools are interactive and run entirely in the browser — no login, no account required.

Education content is structured as a progressive curriculum — each topic builds on the previous, with worked examples and live calculators. No account, no paywall, no ads in the learning content.

Explore the platform

Nine sections — equipment, gas physics, sites, planning and more

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Video library

Reviews, tutorials and dive site footage