TDI Extended Range Diver Course
The TDI Extended Range course is designed for experienced technical divers who wish to safely plan and conduct deeper, open water dives beyond traditional limits while operating within structured, standards-based procedures.
Building on Advanced Nitrox and Decompression Procedures, this program refines equipment configuration, buoyancy, trim, propulsion and team protocols while introducing extended bottom times, advanced gas planning, staged decompression, and contingency management to a maximum depth as specified by current TDI standards.
Emphasis is placed on discipline, awareness, precise dive planning, and effective use of redundant systems to manage elevated risk at depth.
The objective of this course is to equip divers with the
knowledge, skills and mindset required to execute extended range dives with confidence and control, forming a solid platform for further progression in technical diving.
Who Is This Course For:
This course is suitable for certified TDI Advanced Nitrox and Decompression Procedure divers who want to advance into technical diving. If you are looking to improve your skills, gain more experience, or explore deeper underwater areas, this course is for you.
Course Prerequisites:
- Minimum Age: 18 years
- Must be certified as a TDI Advanced Nitrox Diver and TDI Decompression Procedure Diver or equivalent
- Must show proof of at least 100 logged dives
- At least 25 dives must be deeper than 30 meters/100 feet
What Can You Expect To Learn?
The TDI Extended Range Diver course covers the following topics in detail:
History of deep air diving
- Equipment considerations
- Dive tables
- Diving procedures
- Descent considerations
- Ascent considerations
- Technical dive support
- Navigation
Physics
Advanced Gas Physics, such as:
- Pressure review
- Formulas for solving dive planning problems, maximum operating depth (MOD), best mix, and more
Physiology
- Hypoxia
- Oxygen toxicity
- Nitrogen narcosis
- Nitrogen absorption and elimination
- Carbon dioxide toxicity
- Carbon monoxide
- Hyperthermia
- Hypothermia
Decompression Options
- Air
- Nitrox
- Oxygen
Dive planning
- Operation planning
- Team planning
- Emergency planning
Some Essential Skills You Will Need To Demonstrate Include:
- Use the START check before each dive
- Identify and reduce stress
- Follow gas matching rules
- Maintain full buoyancy and keep moving without moving arms or legs
- Be aware of your buddy and team using signals and positions
- Handle deco gas and additional bottom gas
- Release and recover cylinders while remaining stable
- Clearly confirm gas switch with your buddy at depth
- Deploy lift bag from depth and use as backup buoyancy
- Perform air-sharing ascents with a mask-less diver
- Create a backup decompression plan after losing gas
- Remove and change mask and deploy backup mask
- Underwater and on the surface to 30 meters/100 feet Support the diver by pulling and reducing pressure
- Complete a 15-meter/50-foot horizontal breath-hold swim at depth without a mask
- Follow the dive plan to the fullest extent
- Switch off and isolate the faulty regulator at depths greater than 40 meters/130 feet
- Use proper navigation methods for each dive
- Perform staged decompression using an ascent reel and lift bag on two dives
- Pull a simulated unconscious diver to a 9-meter/30-foot ascent line and practice an emergency ascent
What’s In It For You?
After successfully completing this course, you may dive without direct supervision as long as:
- The dives match your training level
- The dive locations match your training areas
- The environmental conditions remain the same as your training
Graduates can also enroll in:
- TDI Advanced Wreck
- TDI Trimix
- TDI Advanced Trimix courses
TDI Extended Range Divers Minimum Requirements:
- Pass the written exam with at least 80%
- Complete 100% of the corrections with instructor guidance
- Complete all open water dives correctly
- Demonstrate the ability to make responsible decisions during dive planning and execution
How To Take This Course:
- Available as an online course - start e-learning today
- Find an instructor for this course
- Find your local dive center
Frequently Asked Questions
Why study deep air versus trimix?
In many areas, helium is scarce or unavailable. Extended Range teaches safe deep-air techniques in areas where trimix cannot be used.
Will I experience nitrogen narcosis during training?
Yes – depth narcosis. This course educates the senses, recognition and control functions with its effects.
Do I need new equipment for this course?
Twinsets, redundant regulators, two-stage cylinders, reels/SMBs and technical-rated gear will be required. We instruct all divers in the proper configuration.
Is this course dangerous?
Every serious technical dive is dangerous. This program provides state-of-the-art risk mitigation, equipment standards and emergency response to ensure safe practice.
What happens after Extended Range?
You can move on to Trimix, Advanced Trimix, and Advanced Rack, which open up depth and atmosphere far beyond the entertainment levels.
Dive Deeper Than Ever Before
The most amazing dives on Earth are done at depth. With the TDI Extended Range Diver course at Blue Water Ascent, you will be able to explore them safely and with confidence thanks to the ability, discipline and technical skills.
