Extended range diving

Extended Range Diving

 

Extended range diving is a more advanced form of decompression diving. It refers to dives where you use air as the primary bottom gas and extend your limits beyond standard decompression protocols. The equipment, procedures, and risk management are more complex than in basic decompression diving.

At this level, divers must demonstrate superior trim, propulsion (e.g. back-kick), buoyancy control, and gas management. Deeper dives increase the influence of narcosis; recognising its onset and assessing your functional degradation are essential skills. Additionally, gas density becomes a limiting factor when breathing air below about 40 m.

TDI Extended range

 

TDI’s extended range course permits dives to 55 m (180 ft) using air with appropriate decompression gas support. That said, many extended-range dives are conducted in the 30-40 m (100-130 ft) band to prioritise bottom time while maintaining safer exposure levels. I do not personally endorse deep-air dives beyond 30m. In my view, helitrox is a safer bridge between standard decompression procedures and full trimix diving.

The Deco 50 (offered by Dive Raid) illustrates a transitional program: it uses trimix to mitigate narcosis while still extending range. See the decompression courses page for details.

 

Dive Raid’s Deco 50 course is outlined on the decompression courses page. It includes the use of trimix to reduce narcosis.

 

The Deco 50 and helitrox courses are good preparation for the full Trimix course. For more information, contact me.

Qualification and training limits:

RAID Deco 50

• • Maximum training depth: 50 m (165 ft)

  • Certification: single decompression gas up to 100% O₂ for trimix dives to 50 m

  • Prerequisites: minimum age 18 (or parental consent), Deco 40 Diver (or equivalent), Rescue Diver, O₂ Provider, Deep Diver, Nitrox Diver, at least 100 logged dives

Header image photo credit: James Emery Photo