A disciplined progression into overhead environments.

• Remain in the daylight zone and within clear sight of the entrance.
• Penetration gas is limited to 1,150 litres / 40 cubic feet or one-third of the available starting volume, whichever is less.
• Minimum starting gas volume: 1,150 litres / 40 cubic feet.
• Maximum penetration distance: 60 metres / 200 feet from the surface.
• Maximum depth: 30 metres / 100 feet.
• Minimum starting visibility: 12 metres / 40 feet.
• No planned decompression.
• No restrictions too small for two divers to pass side by side.

• The cavern environment and accident analysis.
• Cavern formation and environmental hazards.
• Equipment and dive planning.
• Cavern-diving skills and procedures.
• Teamwork and communication.
• Buoyancy, breathing, trim, propulsion and awareness.
• Prevention and management of problems and emergencies.

• Deploy and retrieve a primary reel or spool, including tie-offs and placements.
• Assist a teammate deploying and retrieving the primary reel.
• Follow a line without visibility using touch-contact and bump-and-go techniques.
• Deploy a safety reel or spool.
• Respond to light failure and practice gas sharing.

• Complete pre-dive checks and safety drills.
• Install and retrieve a primary reel or spool, tie-offs and placements.
• Protect the cavern environment and assist the teammate managing the primary reel.
• Respond to a primary-light failure by deploying a backup light and signaling teammates.
• Exit while sharing gas for at least 20 metres / 65 feet in good visibility, as both donor and receiver.

• Penetration gas is limited to 1,400 litres / 50 cubic feet or one-third of the available starting volume, whichever is less.
• Minimum starting volume: 2,100 litres / 75 cubic feet; minimum penetration gas: 700 litres / 25 cubic feet.
• Maximum penetration distance: 300 metres / 1,000 feet from the surface.
• Maximum depth: 30 metres / 100 feet.
• Minimum starting visibility: 10 metres / 30 feet.
• No jumps or gaps to offshoot or continuation lines.
• No planned decompression, stage cylinders, DPVs or original exploration.

• The cave environment and accident analysis.
• Landowner relations and conservation.
• Cave formation and environmental hazards.
• Equipment and dive planning.
• Cave-diving skills and procedures.
• Teamwork and communication.
• Buoyancy, breathing, trim, propulsion and awareness.
• Problem prevention, emergency management and cave-diving etiquette.

• Deploy and retrieve a primary reel or spool, including tie-offs and placements.
• Follow a line without visibility using touch-contact and bump-and-go techniques.
• Share gas with eyes open and without visibility.
• Respond to light failure, a lost diver and a lost line.

• Complete pre-dive checks and safety drills.
• Deploy and retrieve the primary guideline.
• Follow a line without visibility using touch-contact and bump-and-go techniques.
• Share gas with eyes open and without visibility.
• Follow a guideline for at least 15 metres / 50 feet without a mask.
• Deploy a safety reel or spool and demonstrate appropriate propulsion techniques.
• Respond to light failure, a lost diver and a lost line.

• Penetration is limited to one-third of the available starting gas volume.
• Minimum starting volume: 2,100 litres / 75 cubic feet; minimum penetration gas: 700 litres / 25 cubic feet.
• Maximum depth: 40 metres / 130 feet.
• Minimum starting visibility: 6 metres / 20 feet.
• No DPVs.

• Dive planning and complex navigation.
• Circuits, traverses and directional and non-directional markers.
• Cave-diving skills and procedures, including restrictions.
• Teamwork, communication and task loading.
• Problem prevention, emergency management and cave-diving etiquette.

• Complex navigation with jumps, gaps and T-intersections.
• No-visibility line following with touch-contact and bump-and-go techniques.
• Entanglement, line cutting and line repair.

• Complete pre-dive checks and safety drills.
• Master buoyancy, trim and propulsion while task loaded.
• Execute complex navigation, circuits and traverses.
• Follow the line without visibility using touch-contact and bump-and-go techniques.
• Complete gas-sharing and emergency scenarios.
• Negotiate restrictions and respond to entanglement, line cuts and line repairs.

• Complete four cave dives with at least 240 minutes of accumulated bottom time at two different sites.
• At least two of the dives must be 75 minutes or longer.
• All remaining course requirements must be met.

The certification agency and course are agreed when planning your training. TDI and NSS-CDS have their own requirements and course structures; completing a course does not automatically award both certifications. Certification is earned by meeting the applicable knowledge, skills and performance requirements.

Yes. The progression can be planned as one continuous course or in separate blocks. We agree the sequence and dates around your experience, availability and training objectives, with a review of readiness before continuing to the next level.

Use the training reservation page to select your course and preferred dates. Share your certifications, recent experience and configuration so we can review the plan with you. Check the inclusions and exclusions below and read the booking policies before committing to your trip.