TDI Cavern Diver
Enter the overhead environment, master cavern procedures, and develop the discipline required for safe cavern diving
Duration
2 days, 4 dives
Max Depth
40m / 130ft
Level
Technical Overhead Environment
Next Step
TDI Intro to Cave Diver
Overview
The TDI Cavern Diver course trains divers to safely conduct dives within the cavern zone, while remaining inside the natural light area of the cave system.
Unlike recreational cavern experiences, this course develops the procedural and technical skills required to:
- plan and execute cavern dives independently,
- manage continuous guidelines,
- operate safely in overhead environments,
- and respond to visibility or gas-related emergencies.
Training focuses on buoyancy control, propulsion techniques, guideline procedures, communication, and emergency management, where discipline and situational awareness are critical.
At N9BO℠, this course is delivered as foundational overhead environment training, building precision, control, and respect for cave environments.
Course Facts
- Course name: TDI Cavern Diver
- Level: Technical overhead environment diver
- Minimum prerequisites: Minimum age 18 (15 with parental consent), SDI Open Water Scuba Diver (or equivalent), Minimum 25 logged dives
- Ratio: Maximum of 4 students per instructor (small groups recommended for quality training)
- Configuration: Cavern diving equipment including reels, lights, guideline systems, and redundant safety equipment
- Depth / environment: Maximum depth 40m / 130ft, Daylight zone only, Maximum penetration 61 linear metres / 200 linear feet from the surface, No decompression diving, No restrictions or tight passages
- Format: Academic development + land drills + cavern dives
- Duration: Typically completed in 2 days (Minimum 4 cavern dives with at least 80 minutes accumulated bottom time, conducted at 2 different sites)
What You’ll Learn
- Plan and execute cavern dives independently
- Deploy and manage primary reels, safety reels, directional markers
- Practice guideline following, touch contact communication, anti-silting propulsion techniques
- Conduct air sharing drills, lost visibility simulations, light failure procedures
- Maintain proper trim and buoyancy, tTeam communication, situational awareness in overhead environments
Prerequisites
- Be at least 18 years old (15 with parental consent).
- Have a minimum of 25 logged dives.
- Hold Open Water Diver certification (or equivalent).
- Deep Diver certification or equivalent experience required for dives deeper than 18m / 60ft
- Be medically fit for diving.
FAQ
No. This course is limited to:
- The daylight zone
- No restrictions
- No decompression diving
It is the foundation before progressing into cave diving.
You must complete:
- Minimum 4 cavern dives
- Minimum 80 minutes total bottom time
- At 2 different cavern sites
Limits are:
- Maximum 61 linear metres / 200 linear feet from the surface
- Daylight zone only
- Rule of thirds gas management applies
You will learn:
- Guideline deployment and navigation
- Touch contact communication
- Zero visibility procedures
- Air sharing inside overhead environments
- Anti-silting propulsion techniques
You are qualified to conduct independent cavern dives within the daylight zone, using continuous guidelines and overhead environment procedures within the limits of your training.
Ready to Enter the Overhead Environment?
Send us your certifications and dive experience. We’ll train you to dive caverns with precision, awareness, and control.
Go Pro with TDI Cavern Instructor
Advance into overhead environment instruction and train divers in cavern procedures, guideline management, and overhead environment safety.
