Rebreather Cavern

This course is designed to develop the minimum skills and knowledge for diving a TDI approved rebreather in cavern and overhead environments within the limits of light penetration; in addition, outline specific hazards associated with rebreather cave diving. The Rebreather Cavern course is not intended to provide instruction for diving in cave environments. The objective of this course is to train divers in the proper planning, procedures, techniques and hazards of rebreather cavern diving.

What you can expect to learn

The TDI Rebreather Cavern Diver Course takes an in-depth look at all of the following and more:

• Policies for rebreather cavern diving
• Psychological considerations
• Equipment considerations
  • Bailout cylinder options
  • Rebreather configuration options
  • Scrubber options
  • Buoyancy compensator device (BCD) / harness options
  • Reel options
  • Proper weighting
  • Equipment configurations
• Communication
  • Hand signals
  • Light signals
  • Touch contact signals
• Swimming techniques
  • Body posture / trim
  • Buoyancy control and rebreather weighting
  • Line following techniques
  • Propulsion techniques
• Physiology
  • Breathing techniques
  • Stress management
• Cave environment
  • Geology
  • Local access requirements
  • Land owner relations
• Conservation
• Problem solving
  • Equipment failure
  • Silting conditions
• Accident analysis
• Review of dive tables and decompression theory
• Cavern diving with Open Circuit (OC) divers
  • Bailout configuration requirements
  • Out of gas emergencies
• Cavern diving etiquette

Course Equipment Requirements

• A complete TDI approved rebreather
• Minimum of 1 rebreather enabled-computer or PO₂ monitoring device
• Bailout cylinder(s) with volume appropriate for the dive
• Bailout regulator(s) equipped with pressure gauge and low pressure off board (quick connect) gas supply hose
• Access to an oxygen analyzer (instructor may supply)
• Buoyancy compensator device (BCD)
• Exposure suit adequate for cavern environment
• Mask and fins
• Line cutting device
• Safety reel with a minimum of 37 metres / 125 feet of guideline
• One primary reel with a length appropriate for intended dive
• Three battery powered lights; 1 primary and 2 back-ups, each with a burn time suitable for the planned dive time
• Slate or wet notes and pencil
• Submersible dive tables or backup dive computer
• Three directional line arrows
• Weight system Instructor must use

Course Prerequisites

• Minimum age 18
• Minimum certification requirement: TDI CCR Air Diluent Diver, or equivalent
• Provide proof of a minimum of 25 logged dives and 25 hours on the rebreather unit used in training