Hydrogen Gas Shows Promise for Deep Sea Diving Safety Issues
- Authors
- Richard J. Harris, Craig J. Challen, Simon J. Mitchell
- Journal
- Diving and Hyperbaric Medicine
- Year
- 2024
- DOI
- 10.28920/dhm54.1.65-68
- Study Type
- Human
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- New Zealand
- Health Condition
- High-Pressure Neurological Syndrome
- Body System
- Nervous System
TL;DR
Using a mix of helium, oxygen, and hydrogen for deep-sea diving may reduce the risk of a dangerous condition called HPNS without causing other problems.
Key Finding
A single diver breathing hydrogen-containing gas (helihydrox) at 230 meters experienced improvement in high-pressure neurological syndrome symptoms that had previously affected them at similar depths, with no observed adverse effects.
Summary
This case report describes a single deep-sea dive to 230 meters where a diver breathed a gas mixture containing hydrogen (helihydrox) instead of traditional diving gases. At extreme depths, divers can experience a neurological condition called high-pressure neurological syndrome (HPNS) that causes tremors and other symptoms. The diver who had previously experienced these symptoms at similar depths reported improvement when using the hydrogen-containing mixture, with no observed harmful effects during this dive.
Practical Takeaway
This is a single case report from one extreme deep-diving expedition and does not apply to hydrogen water or typical health contexts. The study explores hydrogen as a specialized breathing gas for professional deep-sea diving under extreme pressure conditions—a completely different application from drinking hydrogen-enriched water. Much more research would be needed before any conclusions could be drawn about hydrogen's safety or effects in this specialized diving context.
Abstract
Bounce diving with rapid descents to very deep depths may provoke the high-pressure neurological syndrome (HPNS). The strategy of including small fractions of nitrogen in the respired gas to produce an anti-HPNS narcotic effect increases the gas density which may exceed recommended guidelines. In 2020 the 'Wetmules' dive team explored the Pearse Resurgence cave (New Zealand) to 245 m breathing trimix (approximately 4% oxygen, 91% helium and 5% nitrogen). Despite the presence of nitrogen, one diver experienced HPNS tremors beyond 200 m. The use of hydrogen (a light yet slightly narcotic gas) has been suggested as a solution to this problem but there are concerns, including the potential for ignition and explosion of hydrogen-containing gases, and accelerated heat loss. In February 2023 a single dive to 230 m was conducted in the Pearse Resurgence to experience hydrogen as a breathing gas in a deep bounce dive. Using an electronic closed-circuit rebreather, helihydrox (approximately 3% oxygen, 59% helium and 38% hydrogen) was breathed between 200 and 230 m. This was associated with amelioration of HPNS symptoms in the vulnerable diver and no obvious adverse effects. The use of hydrogen is a potential means of progressing deeper with effective HPNS amelioration while maintaining respired gas density within advised guidelines.