"You don't want to be doing physiological experiments at 300 meters' depth".

This article explores the challenges of deep-sea diving and the search for a solution to withstand underwater pressure beyond the body's natural limits. It discusses the use of helium as a means to counteract the effects of narcosis and oxygen toxicity, but notes its limitations at depths beyond 300 meters. The article introduces the concept of breathing hydrogen as a potential solution and describes the formation of the H2 Working Group, which aims to investigate the use of hydrogen in deep-sea diving. It provides historical context, highlights the risks involved, and discusses the motivations behind this endeavor. Additionally, the article discusses the use of hydrogen gas for deep cave diving, acknowledging concerns about its safety and the lack of available data for decompression calculations. Despite skepticism from some experts, a diver named Harry Harris successfully used hydrogen in the Pearse Resurgence cave, reaching depths that had not been reached before. The article delves into the risks and challenges associated with this type of diving and explores the motivations behind it. [Extracted from the article]